Air duct structure suitable for large-diameter cross-flow fan and air conditioner

Abstract

The application discloses a kind of wind channel structure and air conditioner suitable for large-diameter cross-flow fan, including air inlet grille, evaporator, cross-flow fan, volute tongue and volute, the volute tongue is formed with the volute between cross-flow air duct, the cross-flow air duct has air inlet and air outlet, the cross-flow fan is set in the cross-flow air duct, the diameter of the cross-flow fan is D: the size parameter of the air inlet grille is compatible with the diameter of the cross-flow fan;The evaporator is multiple-fold evaporator, and the multiple-fold evaporator extends along the airflow direction and is bent;The profile of the volute is sequentially and smoothly connected by air inlet section, volute involute section and air outlet section, and the volute involute section is composed of a spline curve.The application, by the ratio of the width L of the air inlet and the diameter D of the cross-flow fan, and the reasonable layout of the angle and spatial position of the three-fold evaporator, effectively solves the contradiction between large-diameter fan and small-sized machine under the premise of constant diameter of the cross-flow fan.

Description

Technical Field

[0001] This invention relates to the field of air conditioner structure technology, and in particular to a duct structure and air conditioner suitable for large-diameter cross-flow fans. Background Technology

[0002] The design trends of wall-mounted air conditioner indoor units are polarized. On the one hand, users' demand for large air volume and rapid cooling and heating is driving the diameter of cross-flow fans to continuously increase; on the other hand, home environments are increasingly demanding thinner and more compact air conditioners. How to balance the contradiction between the diameter of the cross-flow fan (which determines the upper limit of air volume) and the duct space (which determines the lower limit of the overall width) has become the core constraint of duct structure design.

[0003] In the existing duct structure design of wall-mounted air conditioner indoor units, key parameters such as the air inlet width, the number and angle of evaporator folds, the volute profile, and the volute tongue profile are mostly determined empirically or based on conventional fan diameters. When using larger diameter cross-flow fans, the existing duct structure has the following technical defects: Firstly, the mismatch between the air inlet width and the fan diameter leads to increased air intake resistance or an increase in the overall width of the device. In the current design, the air inlet width is not optimized for large-diameter fans. When the fan diameter increases, if the air inlet is not proportionally wide enough, the airflow speed will be too high, the resistance will increase, and the air volume will decrease. If the air inlet is excessively widened, it will directly lead to an increase in the overall width of the device, affecting the slim and lightweight appearance.

[0004] Secondly, the evaporator arrangement is incompatible with the large-diameter fan, affecting heat exchange efficiency and overall unit height. Existing designs often employ a two- or three-fold structure, but the angles of each fold and the relative positions of the evaporator and fan are not systematically matched to the fan diameter, resulting in low heat exchange efficiency.

[0005] Third, the volute profile design lacks optimization for large-diameter fans, resulting in significant airflow losses. Existing volute profiles are mostly simple circular arc connections, which cannot adapt to the larger flow rates and higher velocities brought by large-diameter fans, leading to airflow separation and increased vortex losses.

[0006] Fourth, the volute tongue design is unreasonable, resulting in poor airflow and high noise. As a key airflow guiding component of the air outlet, the shape of the volute tongue directly determines the airflow direction and noise level. However, when the existing volute tongue design is not properly matched with a large-diameter fan, the airflow is separated and turbulent at the volute tongue, resulting in short airflow distance and high noise.

[0007] In summary, there is an urgent need to design a duct profile structure specifically optimized for large-diameter cross-flow fans, so as to ensure large air volume, low power consumption and excellent air delivery effect while achieving a miniaturized overall size. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings mentioned above by providing a duct structure and air conditioner suitable for large-diameter cross-flow fans, achieving miniaturization of the overall unit size while ensuring large air volume, low power consumption, and excellent air delivery effect.

[0009] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a duct structure suitable for large-diameter cross-flow fans, comprising an air inlet grille, an evaporator, a cross-flow fan, a volute tongue, and a volute casing, wherein a cross-flow duct is formed between the volute tongue and the volute casing, the cross-flow duct having an air inlet and an air outlet, and the cross-flow fan being disposed within the cross-flow duct, wherein the diameter of the cross-flow fan is D. The dimensions of the air intake grille are adapted to the diameter of the cross-flow fan; The evaporator is a multi-fold evaporator, which extends in a bent manner along the airflow direction; The profile of the volute is formed by the smooth connection of the air inlet section, the involute section, and the air outlet section in sequence, and the involute section is composed of spline curves. The volute tongue has a frontal surface facing the cross-flow fan, a guide surface facing away from the cross-flow fan, and an arc surface facing the volute profile.

[0010] Furthermore, the width of the air inlet formed by the air inlet grille is L, which satisfies 1.5D≤L≤1.6D; The distance between the air inlet grille and the top of the evaporator is h1, which satisfies 0.14D≤h1≤0.15D; The evaporator is a three-fold evaporator. The first fold of the evaporator forms an angle θ1 with the horizontal line, satisfying 50°≤θ1≤53°; the second fold of the evaporator forms an angle θ2 with the horizontal line, satisfying 47°≤θ2≤55°; and the third fold of the evaporator forms an angle θ3 with the horizontal line, satisfying 88°≤θ3≤91°. The distance from the top of the first and second folded evaporators to the center O of the cross-flow fan is h2, which satisfies 1.1D≤h2≤1.3D; The distance from the third evaporator to the center O is W1, which satisfies 0.1D≤W1≤0.2D; The distance between the third evaporator and the panel is W2, which satisfies 0.2D≤W2≤0.3D.

[0011] Furthermore, the electric heater is placed horizontally inside the cross-flow duct, and the distance between the electric heater and the first evaporator is R1, and the distance between the electric heater and the second evaporator is R2, where R1=R2=0.13D; The distance from the lower end of the electric heater to the center O of the cross-flow fan is h3, which satisfies 0.7D≤h3≤0.8D; The horizontal distance from the center of the electric heater to the center O of the cross-flow fan is h5, where h5 = 0.05D.

[0012] Furthermore, the involute segment of the volute is controlled and set by design points i2, i3, i4, i5, i6 and i7; Define the angle between the design point i2, the design point i3 and the center O of the cross-flow fan as a2, and define the distance between the center O and the design point i3 as b2; Define the angle between the design point i3, the design point i4 and the center O as a3, and define the distance between the center O and the design point i4 as b3; Define the angle between the design point i4, the design point i5 and the center O as a4, and define the distance between the center O and the design point i5 as b4; Define the angle between the design point i5, the design point i6 and the center O as a5, and define the distance between the center O and the design point i6 as b5; Define the angle formed by the design point i6, the design point i7 and the center O as a6, and define the distance between the center O and the design point i7 as b6; Among them, 12°<a2<18°, 20°<a3<25°, 22°<a4<27°, 20°<a5<25°, 22°<a6<25°, 0.5 D<b2<0.6D, 0.5D<b3<0.6D, 0.6D<b4<0.7D, 0.7D<b5<0.8D, 0.8D<b6<0.9D.

[0013] Furthermore, the width of the flow channel between the top of the volute air inlet section and the outer edge of the cross-flow fan is L3, satisfying 0.1D≤L3≤0.2D; The width of the flow channel between the end of the volute air inlet section and the outer edge of the cross-flow fan is L1, which satisfies 0.04D≤L1≤0.06D; The top of the air inlet section is defined as design point i1, the bottom of the air inlet section is defined as design point i2, and the angle formed by design point i1, design point i2 and the center O is α1, which satisfies 15°≤α1≤17°. Define the angle between the vertical line, the design point i1, and the center O as β, which satisfies 28°≤β≤32°.

[0014] Furthermore, the air outlet section of the volute is a smooth straight line segment, and the angle formed by design point i7, design point i8 and the center O is defined as a7, satisfying 30°<a7<35°; Define the distance between the center O and the design point i8 as b7, satisfying 1.1D < b7 < 1.2D; Define the angle between the horizontal line, the center O, and the design point i8 as a8, satisfying 38°<a8<50°.

[0015] Furthermore, the windward surface of the volute tongue is formed by smoothly connecting design points i9, i10, i11 and i12 in sequence; Define the angle between design point i9, the horizontal line and the center O of the circle as β1, which satisfies 30°≤β1≤35°; Define the angle between design point i9, design point i10 and the center O as a9, which satisfies 3°≤a9≤5°; Define the angle formed by design point i10, center O, and design point i11 as a10, and define the distance between design point i11 and center O as b11; Define the angle formed by design point i11, center O, and design point i12 as a11, and define the distance between design point i12 and center O as b12; Where 15° < a10 < 18°, 8° < a11 < 12°, 0.5D < b11 < 0.6D, and 0.5D < b12 < 0.6D.

[0016] Furthermore, the distance from the design point i9 on the windward side of the volute tongue to the outer edge of the cross-flow fan is L4, satisfying 0.07D≤L4≤0.09D; The distance from the design point i10 to the outer edge of the cross-flow fan is L2, which satisfies 0.05D≤L2≤0.08D.

[0017] Furthermore, the volute tongue air guide surface is composed of straight segments i13~i14 and outwardly convex arcs i14~i16, and the length of the straight segments i13~i14 is L6, satisfying 0.3D<L6<0.5D; The angle formed by the straight line segment and the horizontal line is a9, which satisfies 18°<a9<27°; The angle between the air guide surface of the volute tongue and the straight section of the air outlet of the volute is θ4, which satisfies 15°≤θ4≤19°; The convex arcs i14~i16 are composed of straight segments i14~i15 and circular arcs i15~i16. The straight segments i14~i15 are horizontal and have a length of L7, satisfying 0.15D < L7 < 0.17D. The radius of the arcs i15~i16 is R3, which satisfies 15mm≤R3≤20mm; The radius of the arc surface of the volute tongue facing the volute profile is R4, satisfying 5mm≤R4≤8mm.

[0018] Another technical solution proposed in this application is an air conditioner, including the above-mentioned air duct structure suitable for large-diameter cross-flow fans.

[0019] The beneficial effects of this invention are reflected in: (1) The overall size of the machine is reduced, achieving a lightweight and thin design. This invention effectively solves the contradiction between a large-diameter fan and the miniaturization of the whole machine by limiting the ratio of the air inlet width L to the diameter D of the cross-flow fan, and by rationally arranging the angles and spatial positions of each fold of the three-fold evaporator, while keeping the diameter of the cross-flow fan unchanged.

[0020] (2) Significantly increased airflow and improved energy efficiency ratio. This invention, through optimized design of each bend angle of the evaporator and a spline curve structure controlled by design points i2~i7 for the involute segment of the volute, makes airflow smoother and reduces airflow circulation losses.

[0021] (3) Optimized air supply effect to meet diverse air supply needs. The present invention achieves a 25° angle between the main airflow and the horizontal line by coordinating the design of multiple design points of the volute air outlet section and the volute tongue profile. It also has the dual air supply capabilities of forming a "sky curtain wind" that flows along the ceiling and a "carpet wind" that flows along the ground, resulting in a wider air supply coverage and significantly improved user comfort.

[0022] (4) Noise reduction and sound quality improvement. This invention effectively reduces the eddy and turbulent noise of airflow in the duct by using the smooth transition design of the involute segment spline curve of the volute and optimizing the volute tongue profile. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a partial schematic diagram of the air intake grille of the present invention; Figure 3 This is a schematic diagram of the evaporator structure layout of the present invention; Figure 4 This is a schematic diagram of the electric heater structure layout of the present invention; Figure 5 This is a schematic diagram of the optimized volute structure of the present invention; Figure 6 This is a schematic diagram of the optimized cochlear tongue structure of the present invention; Figure 7 This is a schematic diagram of the cochlear tongue length distribution of the present invention; Figure 8 This is a graph showing the airflow test data of the present invention; Figure 9 This is a schematic diagram of the external flow field simulation data of the present invention; Figure 10 This is a schematic diagram of the noise test data of the present invention.

[0024] In the picture: 1. Air inlet grille; 2. Panel; 3. Evaporator; 4. Electric heater; 5. Cross-flow fan; 6. Volute tongue; 7. Volute casing; 31. First fold evaporator; 32. Second fold evaporator; 33. Third fold evaporator; 61. Windward side of the volute tongue; 62. Air-guiding side of the volute tongue; 63. Arc-shaped surface of the volute tongue; 71. Air inlet section; 72. Volute involute section; 73. Air outlet section; i0, Horizontal line; i1, Design point at the top of the air inlet section; i2, Design point at the end of the air inlet section; i3~i7, Design points of the involute segment of the volute; i8, Design point at the end of the air outlet section; i9~i12, Design points of the windward surface of the volute tongue; i13~i16, Design points of the air guide surface of the volute tongue; i17, Vertical line; O, center of the cross-flow fan; D, diameter of the cross-flow fan. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] This embodiment uses the large-diameter cross-flow fan duct structure of a wall-mounted air conditioner indoor unit as an example for illustration. In recent years, the design trend of wall-mounted air conditioner indoor units has become polarized. On the one hand, users' demand for large air volume and rapid cooling and heating has driven the continuous increase in fan size. On the other hand, the aesthetic requirements for thinner and more compact air conditioners in home environments are increasing. How to balance the contradiction between the cross-flow fan diameter (which determines the upper limit of air volume) and the duct space (which determines the lower limit of the overall unit width) has become the core constraint of duct structure design. This embodiment addresses the above contradiction by providing a duct profile structure specifically optimized for large-diameter cross-flow fans.

[0027] like Figure 1 As shown, the air duct structure for a large-diameter cross-flow fan in this embodiment includes an air inlet grille 1, a panel 2, an evaporator 3, an electric heater 4, a cross-flow fan 5, a volute tongue 6, and a volute casing 7. A cross-flow air duct is formed between the volute tongue 6 and the volute casing 7. The cross-flow air duct has an air inlet and an air outlet. The cross-flow fan 5 is disposed inside the cross-flow air duct, and the diameter of the cross-flow fan 5 is D.

[0028] An air inlet grille 1 is located at the top of the air conditioner panel 2, allowing outside air to enter the air conditioner. The width of the air inlet formed by the air inlet grille 1 is L, and L and the diameter D of the cross-flow fan 5 satisfy the following proportional relationship: 1.5D≤L≤1.6D. When the air inlet width L is less than 1.5D, the air intake area is insufficient, the air intake resistance increases, and the air volume decreases; when L is greater than 1.6D, the overall width of the unit increases, which is not conducive to a slim design. In this embodiment, D=108mm, L=162mm, and L / D=1.5.

[0029] The distance between the air inlet grille 1 and the top of the evaporator 3 is h1. h1 and the diameter D of the cross-flow fan 5 satisfy the following proportional relationship: 0.14D≤h1≤0.15D. If h1 is too small, the airflow channel between the air inlet grille 1 and the evaporator 3 is narrow, increasing the airflow resistance; if h1 is too large, the airflow diffuses excessively before entering the evaporator 3, resulting in uneven velocity distribution and affecting heat exchange efficiency. In this embodiment, h1 = 15.1 mm, and h1 / D = 0.14.

[0030] like Figure 2-3 As shown, evaporator 3 is a three-fold evaporator, consisting of a first-fold evaporator 31, a second-fold evaporator 32, and a third-fold evaporator 33 connected in sequence. Compared with two-fold or four-fold evaporators, the three-fold evaporator structure can obtain the largest heat exchange area in a limited space, while making the airflow velocity distribution more uniform when passing through the evaporator.

[0031] The first evaporator 31 forms an angle θ1 with the horizontal line i0, where θ1 ranges from 50° to 53°. The second evaporator 32 forms an angle θ2 with the horizontal line i0, where θ2 ranges from 47° to 55°. The third evaporator 33 forms an angle θ3 with the horizontal line i0, where θ3 ranges from 88° to 91°.

[0032] If θ1 is too small, the first fold of the evaporator 31 will be too flat, occupying too much horizontal space; if θ1 is too large, the top of the evaporator will be too tilted, affecting the uniformity of airflow between the air inlet grille 1 and the evaporator 3. θ3 being close to 90° makes the third fold of the evaporator 33 essentially vertical. This arrangement can effectively extend the heat exchange path length of the evaporator 3 without increasing the overall thickness of the unit, thus improving heat exchange efficiency. In this embodiment, the preferred values ​​are θ1=52°, θ2=50°, and θ3=90°.

[0033] The distance from the top of the first fold evaporator 31 and the second fold evaporator 32 to the center O of the cross-flow fan 5 is h2. h2 and the diameter D of the cross-flow fan 5 satisfy the following proportional relationship: 1.1D ≤ h2 ≤ 1.3D. The distance from the third fold evaporator 33 to the center O is W1. W1 and the diameter D of the cross-flow fan 5 satisfy the following proportional relationship: 0.1D ≤ W1 ≤ 0.2D. The distance from the third fold evaporator 33 to the panel 2 is W2. W2 and the diameter D of the cross-flow fan 5 satisfy the following proportional relationship: 0.2D ≤ W2 ≤ 0.3D.

[0034] When h2 is too small, the gap between the top of the evaporator 3 and the cross-flow fan 5 is too small, and the airflow cannot be fully mixed after passing through the evaporator, which easily generates turbulence and noise. When h2 is too large, the flow path of the airflow from the evaporator 3 to the cross-flow fan 5 is too long, and the flow resistance increases. The values ​​of W1 and W2 directly affect the relative position between the third-stage evaporator 33 and the cross-flow fan 5, and thus affect the airflow distribution in the duct. In this embodiment, h2=1.2D, W1=0.15D, and W2=0.25D.

[0035] like Figure 4 As shown, the electric heater 4 is placed horizontally inside the cross-flow duct to provide auxiliary heating of the air during heating operation. The distance between the electric heater 4 and the first evaporator 31 is R1, and the distance between the electric heater 4 and the second evaporator 32 is R2, where R1=R2=0.13D. This symmetrical arrangement ensures that the electric heater 4 is located in the center of the airflow channel, guaranteeing uniform heating.

[0036] The distance from the lower end of the electric heater 4 to the center O of the cross-flow fan 5 is h3. h3 and the diameter D of the cross-flow fan 5 satisfy the following proportional relationship: 0.7D≤h3≤0.8D. The horizontal distance from the center of the electric heater 4 to the center O of the cross-flow fan 5 is h5, where h5=0.05D.

[0037] In this embodiment, R1=R2=0.13D, h3=0.75D, and h5=0.05D. Experimental verification shows that when the position parameters of the electric heater 4 satisfy the above relationships, the electric heater 4 will neither interfere with the cross-flow fan 5 nor affect the airflow into the cross-flow fan 5, while simultaneously being in the optimal auxiliary heating position.

[0038] As shown in Figure 5, the profile of the volute 7 is formed by the smooth connection of the air inlet section 71, the volute involute section 72, and the air outlet section 73 in sequence.

[0039] The top of the air inlet section 71 is design point i1, and the bottom of the air inlet section 71 is design point i2. The width of the flow channel between the top of the air inlet section 71 and the outer edge of the cross-flow fan 5 is L3, and L3 and the diameter D of the cross-flow fan 5 satisfy the following proportional relationship: 0.1D≤L3≤0.2D. The width of the flow channel between the bottom of the air inlet section 71 and the outer edge of the cross-flow fan 5 is L1, and L1 and the diameter D of the cross-flow fan 5 satisfy the following proportional relationship: 0.04D≤L1≤0.06D.

[0040] The angle formed by design points i1 and i2 and the center O of the cross-flow fan 5 is defined as a1, where a1 ranges from 15° to 17°. The angle formed by the perpendicular line i17 to the horizontal line i0 and design points i1 and the center O is defined as β, where β ranges from 28° to 32°.

[0041] The width of the inlet section 71 gradually decreases from L3 to L1. This gradually narrowing flow channel structure accelerates and straightens the airflow entering the volute 7. CFD simulations verify that when L3, L1, and a1 meet the above-mentioned ranges, the flow loss in the inlet section 71 is minimized, and the air intake efficiency of the volute 7 is maximized. In this embodiment, L3 = 0.15D, L1 = 0.05D, a1 = 16°, and β = 30°.

[0042] The involute segment 72 of the volute is composed of spline curves. The spline curves are controlled and set by design points i2, i3, i4, i5, i6, and i7.

[0043] Define the angle between design points i2 and i3 and the center O of the cross-flow fan 5 as a2, and the distance between the center O and design point i3 as b2; define the angle between design points i3 and i4 and the center O as a3, and the distance between the center O and design point i4 as b3; define the angle between design points i4 and i5 and the center O as a4, and the distance between the center O and design point i5 as b4; define the angle between design points i5 and i6 and the center O as a5, and the distance between the center O and design point i6 as b5; define the angle between design points i6 and i7 and the center O as a6, and the distance between the center O and design point i7 as b6.

[0044] Wherein: 12°<a2<18° (preferably 14°), 20°<a3<25° (preferably 23°), 22°<a4<27° (preferably 25°), 20°<a5<25° (preferably 21°), 22°<a6<25° (preferably 24°); 0.5D<b2<0.6D, 0.5D<b3<0.6D, 0.6D<b4<0.7D, 0.7D<b5<0.8D, 0.8D<b6<0.9D.

[0045] The design point angles a2~a6 of the involute segment 72 of the volute increase sequentially along the airflow direction, and the distances b2~b6 between each design point and the center O also increase sequentially along the airflow direction, resulting in a smooth, outwardly expanding profile of the involute segment 72. This profile structure allows the airflow to flow smoothly along the inner wall of the volute 7, reducing eddies and flow separation, and improving the utilization rate of airflow kinetic energy. Experimental verification shows that when the parameters at each design point meet the above range, the flow resistance of the volute 7 is minimized, and the duct efficiency is maximized.

[0046] In this embodiment, a2=14°, a3=23°, a4=25°, a5=21°, a6=24°; b2=0.55D, b3=0.55D, b4=0.65D, b5=0.75D, b6=0.85D.

[0047] The air outlet section 73 is a smooth straight line segment. The angle formed by design points i7 and i8 and the center O of the cross-flow fan 5 is a7, and the value of a7 is in the range of 30° < a7 < 35° (preferably 33°). The distance between the center O and the design point i8 is b7, and b7 and the diameter D of the cross-flow fan 5 satisfy the following proportional relationship: 1.1D < b7 < 1.2D. The angle formed by the horizontal line i0 and the center O and design point i8 is a8, and the value of a8 is in the range of 38° < a8 < 50° (preferably 45°).

[0048] The straight-line structure of the air outlet section 73 helps maintain a stable airflow direction at the outlet, reducing airflow diffusion losses. Experiments have verified that the airflow velocity and direction at the outlet are most stable when a7, b7, and a8 meet the above-mentioned ranges. In this embodiment, a7 = 33°, b7 = 1.15D, and a8 = 45°.

[0049] like Figure 6-7 As shown, the volute tongue 6 is located inside the air outlet section 73 of the volute 7, and together with the volute 7, forms the air outlet channel of the cross-flow duct. The volute tongue 6 has a windward surface 61 facing the cross-flow fan 5, a guide surface 62 facing away from the cross-flow fan 5, and an arc surface 63 facing the profile of the volute 7.

[0050] The windward surface 61 of the volute tongue is formed by smoothly connecting design points i9, i10, i11 and i12 in sequence.

[0051] Define the angle formed by design point i9, the horizontal line i0, and the center O of the cross-flow fan 5 as β1, where β1 ranges from 30° to 35°. Define the angle formed by design point i9, design point i10, and the center O as a9, where a9 ranges from 3° to 5°. Define the angle formed by design point i10, the center O, and design point i11 as a10, where a10 ranges from 15° to 18° (preferably 16°). Define the angle formed by design point i11, the center O, and design point i12 as a11, where a11 ranges from 8° to 12° (preferably 10°).

[0052] The distance between design point i11 and the center O is b11, and the distance between design point i12 and the center O is b12. b11 and b12 satisfy the following proportional relationship with the diameter D of the cross-flow fan 5: 0.5D < b11 < 0.6D, 0.5D < b12 < 0.6D.

[0053] The distance from design point i9 on the windward side of the volute tongue 61 to the outer edge of the cross-flow fan 5 is L4. L4 and the diameter D of the cross-flow fan 5 satisfy the following proportional relationship: 0.07D≤L4≤0.09D. The distance from design point i10 to the outer edge of the cross-flow fan 5 is L2. L2 and the diameter D of the cross-flow fan 5 satisfy the following proportional relationship: 0.05D≤L2≤0.08D.

[0054] The windward face 61 of the volute tongue is the part of the volute tongue 6 closest to the cross-flow fan 5, and its shape directly affects the gap width and airflow distribution between the volute tongue 6 and the cross-flow fan 5. The section from design point i9 to i10 is the inlet section where the airflow enters the gap between the volute tongue 6 and the cross-flow fan 5. Its flow channel width gradually decreases from L4 to L2, which accelerates the airflow. The section from design point i10 to i12 is formed by connecting two spline curves, which allows the airflow to smoothly bypass the volute tongue 6.

[0055] In this embodiment, the preferred values ​​are β1=32°, a9=4°, a10=16°, a11=10°, b11=0.55D, b12=0.55D, L4=0.08D, and L2=0.065D.

[0056] The volute tongue guide surface 62 consists of straight segments i13~i14 and convex arcs i14~i16. The length of the straight segments i13~i14 is L6, and L6 and the diameter D of the cross-flow fan 5 satisfy the following proportional relationship: 0.3D < L6 < 0.5D. The angle formed by the straight segments i13~i14 and the horizontal line i0 is a9, and the value of a9 is in the range of 18° < a9 < 27°. The angle formed by the volute tongue guide surface 62 and the straight segment 73 of the volute air outlet is θ4, and the value of θ4 is in the range of 15° ≤ θ4 ≤ 19°.

[0057] The convex arcs i14~i16 are composed of straight segments i14~i15 and circular arcs i15~i16. The straight segments i14~i15 are horizontal and have a length of L7. L7 and the diameter D of the cross-flow fan 5 satisfy the following proportional relationship: 0.15D < L7 < 0.17D. The radius of the circular arcs i15~i16 is R3, and the value of R3 is in the range of 15mm ≤ R3 ≤ 20mm.

[0058] The radius of the arc surface 63 of the volute tongue facing the volute 7-type line is R4, and the value of R4 is in the range of 5mm≤R4≤8mm.

[0059] The volute tongue guide surface 62 is the airflow channel that guides the airflow from the volute tongue 6 to the air outlet. The straight segments i13~i14 guide the airflow, while the outwardly convex arcs i14~i16 diffuse and decelerate the airflow, helping to reduce outlet noise. In this embodiment, L6=0.4D, a9=22°, θ4=17°, L7=0.16D, R3=18mm, and R4=6mm.

[0060] Experiments have shown that when the design parameters of the volute tongue 6 meet the above range, the airflow between the volute tongue 6 and the cross-flow fan 5 is most stable, the vortex loss at the volute tongue is minimal, and the noise is lowest.

[0061] This embodiment verifies the performance advantages of the air duct structure through the following comparative tests: Air volume test: such as Figure 8 As shown, under the same fan speed conditions, an air conditioner using the duct structure of this embodiment was compared with a prototype using a traditional duct structure in terms of airflow volume. The test method was conducted according to the airflow test method specified in GB / T7725-2004 "Room Air Conditioners". The test results show that, at the same fan speed, the airflow volume of this embodiment is increased by 10%, while the power consumption of the fan is comparable to that of the prototype. The test data are as follows. Figure 3 As shown.

[0062] External dimensions comparison: Under the premise of keeping the diameter of the cross-flow fan unchanged, the air conditioner with the air duct structure of this embodiment has a 1%~2% reduction in overall width and a 4%~5% reduction in overall height, realizing the miniaturization and thinning design of the air conditioner.

[0063] Comparison of air supply effects: such as Figure 9 As shown, the prototype's main airflow angle with the horizontal is approximately 20°. When the blades deflect clockwise at a small angle, it helps to create a "sky curtain wind" effect that flows along the ceiling. However, as the deflection angle of the blades increases, the airflow decreases more rapidly, the air delivery capacity weakens, and it becomes difficult to reach the ground activity area. In contrast, the main airflow angle with the horizontal in this embodiment is approximately 25°, and it simultaneously possesses the "carpet wind" air delivery capability that flows along both the ceiling and the ground, resulting in a wider air delivery coverage.

[0064] Noise test: such as Figure 10 As shown, under the same airflow conditions, the noise level of the duct structure in this embodiment is reduced by approximately 1 dB(A) compared to the prototype. Test data are as follows... Figure 5 As shown, the noise reduction mainly comes from the smooth transition of the involute segment spline curve of the volute and the optimization of the volute tongue profile, which effectively reduces the eddy and turbulent noise of the airflow in the duct.

[0065] Example 2 The difference between this embodiment and Embodiment 1 lies in the diameter D of the cross-flow fan 5. In this embodiment, D=96mm, which is suitable for smaller wall-mounted air conditioner indoor units.

[0066] The air inlet width is L = 1.55D = 148.8 mm, h1 = 0.145D = 13.9 mm. The evaporator angles are θ1 = 51°, θ2 = 48°, θ3 = 90°. h2 = 1.15D = 110.4 mm, W1 = 0.12D = 11.5 mm, W2 = 0.22D = 21.1 mm.

[0067] The design parameters of each point of the involute segment 72 of the volute are: a2=15°, a3=22°, a4=26°, a5=23°, a6=24°; b2=0.52D=49.9mm, b3=0.52D=49.9mm, b4=0.62D=59.5mm, b5=0.72D=69.1mm, b6=0.82D=78.7mm.

[0068] The design parameters of each point on the windward side 61 of the volute tongue are: β1=33°, a9=4.5°, a10=16.5°, a11=9.5°, b11=0.52D=49.9mm, b12=0.52D=49.9mm, L4=0.075D=7.2mm, L2=0.06D=5.8mm.

[0069] The test results show that this embodiment also achieves the technical effects of increasing air volume and reducing overall size under the condition of D=96mm.

[0070] Example 3 The difference between this embodiment and embodiments one and two lies in the different angle values ​​of the three-fold evaporator. In this embodiment, θ1=53°, θ2=55°, and θ3=91°.

[0071] Increasing θ1 and θ2 makes the first and second folds of the evaporator more inclined, which can reduce the horizontal space occupied by the evaporator to some extent, but slightly increases the length of the airflow channel between the evaporator and the cross-flow fan. θ3=91° makes the third fold of the evaporator slightly inclined outward, which is beneficial to increasing the windward area of ​​the third fold evaporator and improving the heat exchange efficiency.

[0072] This embodiment is suitable for applications that require high heat exchange efficiency but are relatively insensitive to the overall height of the unit. Other parameters remain the same as in Embodiment 1.

[0073] Example 4 The difference between this embodiment and embodiments one, two, and three lies in the different design point angle values ​​of the involute segment 72 of the volute. In this embodiment, a2=17°, a3=24°, a4=26°, a5=24°, and a6=24.5°.

[0074] The design uses larger angles at each point, increasing the overall unfolding angle of the involute segment 72 of the volute and making the air outlet of the volute 7 more horizontal. This design is suitable for scenarios requiring a larger air outlet angle and emphasizing a "carpet-like" airflow effect. Experiments show that when the angles at each design point are larger, the angle between the main airflow and the horizontal line increases, which is beneficial for the airflow to adhere to the ground.

[0075] The present invention provides an air duct structure and air conditioner suitable for large-diameter cross-flow fans. By limiting the ratio of the air inlet width L to the cross-flow fan diameter D (1.5D≤L≤1.6D), the angle range of the three-fold evaporator (θ1=50°~53°, θ2=47°~55°, θ3=88°~91°), the spline curve shape of the involute segment of the volute controlled by 6 design points (the angles a2~a6 and the distances b2~b6 of each design point meet specific ranges), and the smooth connection structure of multiple design points on the windward and guiding surfaces of the volute tongue, the present invention achieves the technical effects of reducing the overall width by 1%~2%, reducing the overall height by 4%~5%, increasing the air volume by 10%, and reducing the noise by 1dB(A) while keeping the cross-flow fan diameter unchanged.

[0076] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0077] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0078] Additionally, "multiple" refers to two or more.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A duct structure suitable for a large-diameter cross-flow fan, comprising an air inlet grille, an evaporator, a cross-flow fan, a volute tongue, and a volute casing, wherein a cross-flow duct is formed between the volute tongue and the volute casing, the cross-flow duct having an air inlet and an air outlet, the cross-flow fan being disposed within the cross-flow duct, the diameter of the cross-flow fan being D, characterized in that: The dimensions of the air intake grille are adapted to the diameter of the cross-flow fan; The evaporator is a multi-fold evaporator, which extends in a bent manner along the airflow direction; The profile of the volute is formed by the smooth connection of the air inlet section, the involute section, and the air outlet section in sequence, and the involute section is composed of spline curves. The volute tongue has a frontal surface facing the cross-flow fan, a guide surface facing away from the cross-flow fan, and an arc surface facing the volute profile.

2. The duct structure for large-diameter cross-flow fans according to claim 1, characterized in that: The width of the air inlet formed by the air inlet grille is L, which satisfies 1.5D≤L≤1.6D; The distance between the air inlet grille and the top of the evaporator is h1, which satisfies 0.14D≤h1≤0.15D; The evaporator is a three-fold evaporator. The first fold of the evaporator forms an angle θ1 with the horizontal line, satisfying 50°≤θ1≤53°; the second fold of the evaporator forms an angle θ2 with the horizontal line, satisfying 47°≤θ2≤55°; and the third fold of the evaporator forms an angle θ3 with the horizontal line, satisfying 88°≤θ3≤91°. The distance from the top of the first and second folded evaporators to the center O of the cross-flow fan is h2, which satisfies 1.1D≤h2≤1.3D; The distance from the third evaporator to the center O is W1, which satisfies 0.1D≤W1≤0.2D; The distance between the third evaporator and the panel is W2, which satisfies 0.2D≤W2≤0.3D.

3. The duct structure suitable for large-diameter cross-flow fans according to claim 1, characterized in that: The electric heater is placed horizontally inside the cross-flow duct. The distance between the electric heater and the first evaporator is R1, and the distance between the electric heater and the second evaporator is R2, where R1=R2=0.13D. The distance from the lower end of the electric heater to the center O of the cross-flow fan is h3, which satisfies 0.7D≤h3≤0.8D; The horizontal distance from the center of the electric heater to the center O of the cross-flow fan is h5, where h5 = 0.05D.

4. The duct structure suitable for large-diameter cross-flow fans according to claim 1, characterized in that: The involute segment of the volute is controlled and set by design points i2, i3, i4, i5, i6 and i7; Define the angle between the design point i2, the design point i3 and the center O of the cross-flow fan as a2, and define the distance between the center O and the design point i3 as b2; Define the angle between the design point i3, the design point i4 and the center O as a3, and define the distance between the center O and the design point i4 as b3; Define the angle between the design point i4, the design point i5 and the center O as a4, and define the distance between the center O and the design point i5 as b4; Define the angle between the design point i5, the design point i6 and the center O as a5, and define the distance between the center O and the design point i6 as b5; Define the angle formed by the design point i6, the design point i7 and the center O as a6, and define the distance between the center O and the design point i7 as b6; Among them, 12°<a2<18°, 20°<a3<25°, 22°<a4<27°, 20°<a5<25°, 22°<a6<25°, 0.5 D<b2<0.6D, 0.5D<b3<0.6D, 0.6D<b4<0.7D, 0.7D<b5<0.8D, 0.8D<b6<0.9D.

5. The duct structure suitable for large-diameter cross-flow fans according to claim 4, characterized in that: The width of the flow channel between the top of the volute air inlet section and the outer edge of the cross-flow fan is L3, which satisfies 0.1D≤L3≤0.2D; The width of the flow channel between the end of the volute air inlet section and the outer edge of the cross-flow fan is L1, which satisfies 0.04D≤L1≤0.06D; The top of the air inlet section is defined as design point i1, the bottom of the air inlet section is defined as design point i2, and the angle formed by design point i1, design point i2 and the center O is α1, which satisfies 15°≤α1≤17°. Define the angle between the vertical line, the design point i1, and the center O as β, which satisfies 28°≤β≤32°.

6. The duct structure for large-diameter cross-flow fans according to claim 1, characterized in that: The air outlet section of the volute is a smooth straight line segment. The angle formed by the design point i7, the design point i8 and the center O is defined as a7, which satisfies 30° < a7 < 35°. Define the distance between the center O and the design point i8 as b7, satisfying 1.1D < b7 < 1.2D; Define the angle between the horizontal line, the center O, and the design point i8 as a8, satisfying 38°<a8<50°.

7. The duct structure for large-diameter cross-flow fans according to claim 1, characterized in that: The windward surface of the volute tongue is formed by smoothly connecting design points i9, i10, i11 and i12 in sequence. Define the angle between design point i9, the horizontal line and the center O of the circle as β1, which satisfies 30°≤β1≤35°; Define the angle between design point i9, design point i10 and the center O as a9, which satisfies 3°≤a9≤5°; Define the angle formed by design point i10, center O, and design point i11 as a10, and define the distance between design point i11 and center O as b11; Define the angle formed by design point i11, center O, and design point i12 as a11, and define the distance between design point i12 and center O as b12; Where 15° < a10 < 18°, 8° < a11 < 12°, 0.5D < b11 < 0.6D, and 0.5D < b12 < 0.6D.

8. The duct structure for large-diameter cross-flow fans according to claim 7, characterized in that: The distance from the design point i9 on the windward side of the volute tongue to the outer edge of the cross-flow fan is L4, which satisfies 0.07D≤L4≤0.09D; The distance from the design point i10 to the outer edge of the cross-flow fan is L2, which satisfies 0.05D≤L2≤0.08D.

9. The duct structure for large-diameter cross-flow fans according to claim 1, characterized in that: The volute tongue air guide surface is composed of straight segments i13~i14 and outwardly convex arcs i14~i16. The length of the straight segments i13~i14 is L6, which satisfies 0.3D < L6 < 0.5D. The angle formed by the straight line segment and the horizontal line is a9, which satisfies 18°<a9<27°; The angle between the air guide surface of the volute tongue and the straight section of the air outlet of the volute is θ4, which satisfies 15°≤θ4≤19°; The convex arcs i14~i16 are composed of straight segments i14~i15 and circular arcs i15~i16. The straight segments i14~i15 are horizontal and have a length of L7, satisfying 0.15D < L7 < 0.17D. The radius of the arcs i15~i16 is R3, which satisfies 15mm≤R3≤20mm; The radius of the arc surface of the volute tongue facing the volute profile is R4, satisfying 5mm≤R4≤8mm.

10. An air conditioner, characterized in that: Includes the air duct structure suitable for large-diameter cross-flow fans as described in any one of claims 1 to 9.

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