Vertical air conditioner indoor unit

Abstract

The invention discloses a vertical air conditioner indoor unit, and relates to the technical field of vertical air conditioner indoor units. The vertical air conditioner indoor unit comprises a machine shell, a heat exchanger, a centrifugal fan, a volute and a volute tongue. The heat exchanger and the volute are arranged in the machine shell. The centrifugal fan is arranged in the volute; a volute air inlet and a volute air outlet are formed in the volute; the volute tongue is arranged in the volute and protrudes out of the inner wall of the volute. One side of the volute tongue is arranged towards the centrifugal fan, and the other side of the volute tongue is arranged towards the volute air outlet; the windward side of the volute tongue is limited to form a volute tongue curve; the volute tongue curve comprises a first curve and a second curve, and the first curve is arranged corresponding to one side, facing the centrifugal fan, of the volute tongue; the second curve is arranged corresponding to one side, facing the volute air outlet, of the volute tongue; the second curve is connected to the first curve and is tangent to the first curve at a connection point; the first curve is an arc curve, and the second curve is an airfoil curve. The vertical air conditioner indoor unit is large in air outlet amount, and loss is small when airflow flows through the volute tongue.

Description

Technical Field

[0001] This application relates to the technical field of air conditioning, and more particularly to a vertical air conditioning indoor unit. Background Technology

[0002] Centrifugal fans are an important component of air conditioner indoor units. They are typically installed inside a volute casing, whose main function is to guide the gas leaving the fan to its outlet and convert some of the gas's dynamic pressure into static pressure. A volute tongue is usually located at the air outlet of the volute casing. This tongue guides and changes the airflow direction; therefore, the design of the volute tongue plays a crucial role in the aerodynamic performance and noise control of the air conditioner indoor unit.

[0003] In existing technologies, the volute tongue usually adopts a simple arc transition. Although this method is easy to process, it is easy to cause backflow and impact loss when the airflow passes through the volute tongue, and it is also easy to cause BPF noise (BPF noise, namely Blade Passing Frequency noise, is the noise generated by the periodic pressure pulsation when the blades pass through during the operation of the fan).

[0004] The existing volute cannot adequately meet the requirements of air conditioner indoor units. Designing a volute that can avoid backflow, reduce impact loss, or reduce airflow noise is of great significance for improving the performance of air conditioner indoor units. Summary of the Invention

[0005] In view of the shortcomings of the related technologies, this application provides a vertical air conditioner indoor unit, which improves the flow loss at the volute tongue by designing the volute tongue as a multi-arc structure with a smooth transition between conventional arc and special airfoil.

[0006] This application provides a vertical air conditioner indoor unit, comprising:

[0007] The casing has a first cavity and a second cavity defined inside it. The first cavity and the second cavity are distributed along the height direction of the casing, and the second cavity is located above the first cavity. The casing has an air inlet and an air outlet. The air inlet is connected to the first cavity, and the air outlet is connected to the second cavity.

[0008] The heat exchanger is located inside the second chamber;

[0009] A centrifugal fan is located in the first chamber. When the centrifugal fan is running, it draws outside air into the second chamber through the air inlet of the casing. After the air comes into contact with the heat exchanger for heat exchange, it is then output to the room through the air outlet of the casing.

[0010] A volute, disposed within a first cavity; the volute is located at the bottom of the housing; the volute has an air inlet and an air outlet, the air inlet communicating with the first cavity, and the air outlet communicating with the second cavity; the volute includes:

[0011] The volute tongue protrudes from the inner wall of the volute casing; one side of the volute tongue faces the centrifugal fan, and the other side faces the air outlet of the volute casing; the windward side of the volute tongue defines a volute tongue curve; the volute tongue curve includes:

[0012] The first curve corresponds to the side of the volute tongue facing the centrifugal fan;

[0013] The second curve is set on the side of the volute tongue facing the air outlet of the volute; the second curve is connected to the first curve, and the second curve and the first curve are tangent at the connection point;

[0014] The first curve extends to form a hypothetical curve, which is set along the airflow path from the connection point of the second curve and the first curve; the hypothetical curve and the first curve are circular arc curves, and the second curve is an airfoil curve; compared with the hypothetical curve, the second curve is set closer to the first curve.

[0015] This technical solution improves flow loss at the volute tongue by designing the volute tongue curve to include both circular and airfoil curves, making it a multi-segment airfoil structure. The windward surface of the volute tongue facing the centrifugal fan is designed as a circular surface, while the windward surface of the volute tongue facing the air outlet of the volute casing is designed as an airfoil surface, with a smooth transition between the circular and airfoil surfaces. The airfoil surface guides the airflow inside the volute casing to avoid backflow, and the circular surface contacts the airflow flowing into the receiving cavity to prevent localized airflow concentration that could cause flow loss or abnormal noise.

[0016] In some embodiments of this application, the second curve can be extended to form a closed curve, which is a closed airfoil curve. The curvature at the leading edge of the closed curve is greater than that of the first curve, and the second curve is set on the closed curve close to the leading edge.

[0017] This technical solution allows the second curve to extend into a closed asymmetric airfoil curve, making the camber at the leading edge greater than that of the first curve. The second curve is positioned close to the leading edge on the closed curve, so that the camber of the second curve is greater than that of the first curve. This reduces the flow separation at the volute tongue and also reduces the abnormal noise generated when the airflow passes through the volute tongue.

[0018] In some embodiments of this application, a closed curve defines a middle arc, and the middle arc defines a tangent at its intersection with the volute tongue curve; a first plane is defined by the length direction of the volute and the opening direction of the volute air inlet, and the tangent and the first plane define a first included angle α, and the first included angle α and the blade outlet angle β of the centrifugal fan satisfy the relationship: α + β = 180°.

[0019] This technical solution achieves the following relationship by ensuring that the first included angle α and the blade outlet angle β of the centrifugal fan satisfy the formula: α+β=180°. This makes the incoming flow direction at the volute tongue nearly tangent to the windward side of the volute tongue facing the air outlet of the volute casing, thereby further reducing the wind resistance of the volute tongue to the airflow.

[0020] In some embodiments of this application, the inner wall of the volute is provided with a flow guide, which is connected to the side of the volute tongue facing the air outlet of the volute and extends toward the air outlet of the volute to guide the airflow toward the air outlet of the volute; the windward surface of the flow guide is defined by a flow guide curve, which is connected to the end of the second curve away from the first curve, and the flow guide curve and the second curve are tangent at the connection point of the two.

[0021] This technical solution provides a guide section on the side of the volute tongue facing the volute air outlet, which guides the airflow toward the volute air outlet. By making the guide curve tangent to the second curve at the connection point, the windward surface of the guide section and the windward surface of the volute tongue facing the volute air outlet smoothly transition, thereby increasing the guiding effect on the airflow.

[0022] In some embodiments of this application, the guide curve and the second curve are connected to form a third curve. The connection point between the third curve and the first curve is point O. The third curve has the maximum curvature at point A. Point A has a projection point A′ on the chord of the third curve. A first straight line is formed by connecting points O and A′. The length L1 of the first straight line and the length L of the chord of the third curve satisfy the following relationship: L1≥1 / 4L, L1≤1 / 2L.

[0023] This technical solution limits the third curve by ensuring that the length L1 of the first straight line and the length L of the chord of the third curve satisfy the following relationship: L1≥1 / 4L, L1≤1 / 2L.

[0024] In some embodiments of this application, the closed curve is an asymmetric airfoil curve, which is divided into a first airfoil curve and a second airfoil curve by the line connecting its leading edge and trailing edge. The camber of the first airfoil curve is greater than that of the second airfoil curve, and at least part of the second curve is located on the first airfoil curve. The guide curve is located on the first airfoil curve.

[0025] In this technical solution, the closed curve is an asymmetric airfoil curve. By dividing the closed curve into a first airfoil curve and a second airfoil curve, the positions of the second curve and the guide curve on the closed curve, as well as the shapes of the second curve and the guide curve, are further defined.

[0026] In some embodiments of this application, the second airfoil curve is positioned closer to the first curve, and the curvature of the second airfoil curve is greater than that of the first curve.

[0027] This technical solution, by comparing the second airfoil curve with the first curve, not only more intuitively illustrates that the first curve has a smaller curvature and that the windward surface formed by the first curve has a good guiding effect on the airflow, but also further defines the second curve.

[0028] In some embodiments of this application, the outer diameter of the centrifugal fan blades is D, the radius of the first curve is R, and R and D satisfy the following relationship: R≥0.07D, R≤0.15D.

[0029] This technical solution uses a centrifugal fan with an outer diameter of D and a first curve radius of R, where R and D satisfy the following relationship: R ≥ 0.07D, R ≤ 0.15D. This ensures that the airflow resistance is low when passing between the centrifugal fan and the volute tongue, and that the volute tongue effectively guides the airflow. It avoids a small distance between the windward side of the volute tongue and the outer edge of the centrifugal fan, which would result in high airflow resistance. At the same time, it also avoids a large distance between the windward side of the volute tongue and the outer edge of the centrifugal fan, which would reduce the guiding effect of the volute tongue on the airflow.

[0030] In addition, this application also provides a vertical air conditioner indoor unit, comprising:

[0031] The casing has a first cavity and a second cavity defined inside it. The first cavity and the second cavity are distributed along the height direction of the casing, and the second cavity is located above the first cavity. The casing has an air inlet and an air outlet. The air inlet is connected to the first cavity, and the air outlet is connected to the second cavity.

[0032] The heat exchanger is located inside the second chamber;

[0033] A centrifugal fan is located in the first chamber. When the centrifugal fan is running, it draws outside air into the second chamber through the air inlet of the casing. After the air comes into contact with the heat exchanger for heat exchange, it is then output to the room through the air outlet of the casing.

[0034] A volute, located within the first cavity; the volute is situated at the bottom of the housing; a centrifugal fan is located inside the volute; the volute has an air inlet and an air outlet, the air inlet communicating with the first cavity, and the air outlet communicating with the second cavity; the volute comprises:

[0035] The volute tongue is located inside the volute and protrudes from the inner wall of the volute; one side of the volute tongue faces the centrifugal fan, and the other side of the volute tongue faces the air outlet of the volute.

[0036] Among them, the windward surface of the volute tongue facing the centrifugal fan is a circular arc surface, and the windward surface of the volute tongue facing the air outlet of the volute casing is an airfoil surface, with a smooth transition between the circular arc surface and the airfoil surface.

[0037] In some embodiments of this application, the inner wall of the volute is provided with a flow guide, which is connected to the side of the volute tongue facing the air outlet of the volute and extends toward the air outlet of the volute; the windward surface of the flow guide smoothly transitions with the windward surface of the volute tongue facing the air outlet of the volute, and the windward surface of the flow guide is an airfoil.

[0038] This technical solution involves setting a guide section on the side of the volute tongue facing the air outlet of the volute shell, and using the guide section to guide the airflow towards the air outlet of the volute shell. By designing the windward surface of the guide section as an airfoil, on the one hand, the guide section can better guide the airflow, and on the other hand, the guide section can extend to the side of the volute tongue facing the air outlet of the volute shell, thereby increasing the guiding effect of the volute tongue on the airflow.

[0039] In the above embodiments, a vertical air conditioner indoor unit combines a conventional circular arc with a special airfoil profile to make the volute a multi-segment airfoil structure; the windward surface of the volute facing the centrifugal fan is designed as a circular arc surface, which contacts the airflow flowing into the receiving cavity to avoid local airflow concentration that could cause flow loss or abnormal noise; the windward surface of the volute facing the air outlet of the volute is designed as an airfoil surface, which guides the airflow inside the volute to avoid backflow; and the circular arc surface and the airfoil surface are smoothly transitioned to improve flow loss at the volute. Attached Figure Description

[0040] Figure 1 A structural schematic diagram of a vertical air conditioner indoor unit according to some embodiments is shown;

[0041] Figure 2 A schematic diagram of the structure of a vertical air conditioner indoor unit without a baffle plate is shown according to some embodiments;

[0042] Figure 3 A schematic diagram of the internal structure of a vertical air conditioner indoor unit according to some embodiments is shown;

[0043] Figure 4 A schematic diagram of the centrifugal fan and volute assembly in a vertical air conditioner indoor unit according to some embodiments is shown;

[0044] Figure 5 A schematic diagram of the volute structure in a vertical air conditioner indoor unit is shown according to some embodiments;

[0045] Figure 6 A schematic diagram of the volute in a vertical air conditioner indoor unit at another angle is shown according to some embodiments;

[0046] Figure 7 A plan view of the volute in a vertical air conditioner indoor unit is shown according to some embodiments;

[0047] Figure 8This diagram illustrates the flow path of airflow through the volute tongue in the prior art.

[0048] Figure 9 This diagram illustrates the flow path of airflow when the volute tongue curve is an airfoil curve.

[0049] Figure 10 A schematic diagram of the airflow path as it passes through the volute in a vertical air conditioner indoor unit according to some embodiments is shown.

[0050] Figure 11 A schematic diagram of the volute curve in a vertical air conditioner indoor unit according to some embodiments is shown;

[0051] Figure 12 A schematic diagram comparing the extended curve with the second curve and the first curve with the second airfoil curve in a vertical air conditioner indoor unit according to some embodiments is shown;

[0052] Figure 13 A schematic diagram of a first included angle in a vertical air conditioner indoor unit according to some embodiments is shown;

[0053] Figure 14 A schematic diagram of the blade outlet angle in a vertical air conditioner indoor unit according to some embodiments is shown;

[0054] Figure 15 A schematic diagram of a closed curve in a coordinate system is shown in a vertical air conditioner indoor unit according to some embodiments;

[0055] Figure 16 A schematic diagram of a third curve in a vertical air conditioner indoor unit according to some embodiments is shown;

[0056] Figure 17 A schematic diagram of an asymmetric airfoil closed curve in a vertical air conditioner indoor unit according to some embodiments is shown.

[0057] In the picture,

[0058] 100. Casing; 200. Baffle plate; 300. Heat exchanger; 400. Volute; 500. Centrifugal fan; 600. Guide ring; 700. Closed curve; 800. First plane; 900. Tangent;

[0059] 101. Air inlet of the casing; 102. Air outlet of the casing;

[0060] 401. Air inlet of the volute; 402. Air outlet of the volute; 403. Air outlet duct; 404. Receiving cavity;

[0061] 410. Front panel; 420. Enclosure panel; 430. Volute tongue; 440. Air guide section; 450. Air outlet section; 460. Body section;

[0062] 431. First curve; 432. Second curve; 433. Hypothetical curve;

[0063] 441. Flow curve;

[0064] 451. Extension segment; 452. Extended segment; 4521. Extended curve; 4521a. First extended curve; 4521b. Second extended curve;

[0065] 701. Mid-arc line; 702. Third curve; 703. Chord length. Detailed Implementation

[0066] To make the objectives and implementation methods of this application clearer, the exemplary implementation methods of this application will be clearly and completely described below with reference to the accompanying drawings of the exemplary embodiments of this application. Obviously, the exemplary embodiments described are only some embodiments of this application, and not all embodiments.

[0067] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0068] The terms "first," "second," "third," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar or related objects or entities, and do not necessarily imply a specific order or sequence, unless otherwise specified. It should be understood that such terms are interchangeable where appropriate.

[0069] The terms “include” and “have”, and any variations thereof, are intended to cover but not exclusively include, for example, a product or device that includes a range of components is not necessarily limited to all of the components that are clearly listed, but may include other components that are not clearly listed or that are inherent to such product or device.

[0070] The vertical air conditioner indoor unit provided in this application can have various implementation forms. For example... Figures 1-3 This is a specific embodiment of the vertical air conditioner indoor unit of this application. The vertical air conditioner indoor unit includes a housing 100, which is used to form the overall appearance of the air conditioner outdoor unit.

[0071] The housing 100 has a top and a bottom. The top and bottom of the housing 100 are opposite ends. The direction from the top to the bottom of the housing 100 is the height direction of the housing 100. The left and right sides of the housing 100 are opposite sides. The direction from the left to the right side of the housing 100 is the length direction of the housing 100. The front and rear sides of the housing 100 are opposite sides. The direction from the front to the rear side of the housing 100 is the thickness direction of the housing 100.

[0072] In practical applications, the rear of the housing 100 is usually positioned facing the wall, while the front of the housing 100 is usually positioned facing the user.

[0073] like Figure 1 and Figure 2 As shown, the housing 100 includes a housing air inlet 101, which is connected to the interior of the housing 100. Indoor air enters the interior of the housing 100 through the housing air inlet 101. The housing air inlet 101 is located on the front side of the housing 100 and is positioned near the bottom of the housing 100.

[0074] like Figure 1 and Figure 2 As shown, the housing 100 includes a housing air outlet 102, which is connected to the interior of the housing 100. Air inside the housing 100 is output to the room through the housing air outlet 102. The housing air outlet 102 is located on the front side of the housing 100 and is located near the top of the housing 100.

[0075] like Figure 1 and Figure 2 As shown, the housing 100 is connected to a baffle plate 200, which is provided at the housing air outlet 102 in an openable manner to open or close the housing air outlet 102.

[0076] The housing 100 has a first cavity defined inside, which is located near the top of the housing 100, and the housing air inlet 101 is connected to the first cavity.

[0077] The housing 100 has a second cavity defined inside. The first cavity and the second cavity are distributed along the height direction of the housing 100, and the second cavity is located above the first cavity. The second cavity is located near the bottom of the housing 100, and the air outlet 102 of the housing is connected to the second cavity.

[0078] like Figure 3 As shown, the above-mentioned vertical air conditioner indoor unit includes a heat exchanger 300, which is installed in the casing 100 and located in the second cavity. Air in the second cavity comes into contact with the heat exchanger 300 and is heated by the heat exchanger 300 to form air conditioning air, thus meeting the user's cooling or heating needs. It should be noted that the air conditioning air can be cold air, hot air, or even ambient temperature air.

[0079] The heat exchanger 300 is positioned near the top of the casing 100 and near the air outlet 102 of the casing, so that the air can be promptly discharged into the room through the air outlet 102 of the casing after heat exchange through the heat exchanger 300.

[0080] like Figure 3 and Figure 4 As shown, the above-mentioned vertical air conditioner indoor unit includes a centrifugal fan 500. The centrifugal fan 500 is installed in the casing 100 and located in the first cavity. When the centrifugal fan 500 is running, indoor air is introduced into the second cavity through the air inlet 101 of the casing and the first cavity. After heat exchange in the heat exchanger 300 to form air conditioning air, the air conditioning air flows into the room through the air outlet 102 of the casing.

[0081] The centrifugal fan 500 is located below the heat exchanger 300 and at the bottom of the casing 100. The centrifugal fan 500 is positioned close to the air inlet 101 of the casing to increase the air intake effect of the centrifugal fan 500 on the indoor air, thereby enabling the vertical air conditioner indoor unit to have a better air intake volume.

[0082] like Figure 3 As shown, the vertical air conditioner indoor unit includes a volute 400, which is installed in the housing 100 and located in the first cavity. The volute 400 is located at the bottom of the housing 100. The volute 400 is used to install a centrifugal fan 500, which is located inside the volute 400.

[0083] like Figure 4 and Figure 5 As shown, a volute air inlet 401 is formed on the volute 400. The volute air inlet 401 is connected to the first cavity. The volute air inlet 401 is correspondingly set with the housing air inlet 101. Indoor air enters the interior of the volute 400 through the housing air inlet 101 and the volute air inlet 401.

[0084] like Figure 4 As shown, the volute 400 is connected to a guide ring 600, which is located at the air inlet 401 of the volute and is used to guide the airflow into the interior of the volute 400.

[0085] It should be noted that the guide ring 600 is located on the outside of the receiving cavity 404 so that the guide ring 600 can guide the airflow from the volute inlet 401 into the interior of the volute 400.

[0086] like Figure 5 As shown, a volute air outlet 402 is formed on the volute 400. The volute air outlet 402 is located close to the heat exchanger 300. The air inside the volute 400 is output from the volute 400 through the volute air outlet 402. After the air is output from the volute 400, it comes into contact with the heat exchanger 300 to exchange heat and form air conditioning air.

[0087] like Figure 7 As shown, the volute 400 includes a body portion 460, within which a receiving cavity 404 is defined. A centrifugal fan 500 is installed within the receiving cavity 404. The volute air inlet 401 and the volute air outlet 402 are respectively connected to the receiving cavity 404. When the centrifugal fan 500 operates, indoor air is drawn into the receiving cavity 404 from the casing air inlet 101 and then into the casing air inlet 401, and then enters the casing 100 through the volute air outlet 402 to exchange heat with the heat exchanger 300.

[0088] like Figure 7 As shown, the inner wall of the receiving cavity 404 is adapted to the airflow path to prevent the inner wall of the receiving cavity 404 from significantly obstructing the airflow when it flows inside the receiving cavity 404.

[0089] The air flows roughly in a spiral path after being introduced into the receiving cavity 404 by the centrifugal fan 500. As the air flows in the receiving cavity 404, the inner wall of the receiving cavity 404 is a spiral surface so that the inner wall of the receiving cavity 404 is adapted to the airflow path.

[0090] The spiral surface defines a spiral line, which is set along the airflow path. According to the airflow direction, the spiral line has a starting point and an ending point, and the airflow flows from the starting point to the ending point along the airflow path.

[0091] like Figure 7 As shown, the volute 400 includes an air outlet 450 connected to the main body 460; the air outlet 450 defines an air outlet duct 403 for connecting the receiving cavity 404 and the second cavity; the volute air outlet 402 is located in the air outlet 450. When the centrifugal fan 500 operates, air from the receiving cavity 404 is discharged through the air outlet duct 403 and the volute air outlet 402 to the interior of the housing 100.

[0092] like Figure 7 As shown, the air outlet 450 includes an extension section 451, which forms the inner wall of one side of the air outlet duct 403; the windward side of the extension section 451 is defined by an extension curve, one end of which is connected to the end of the spiral line, and the other end of which extends toward the volute air outlet 402.

[0093] like Figure 7 As shown, the air outlet 450 includes an extension section 452, which forms the inner wall of the other side of the air outlet duct 403. The extension section 452 and the extension section 451 are respectively disposed on opposite sides of the airflow path. The extension section 452 and the extension section 451 together define the air outlet duct 403 and the volute air outlet 402.

[0094] like Figure 11As shown, the extension segment 452 defines an extension curve 4521, one end of which is located near the receiving cavity 404, and the other end of which extends toward the volute air outlet 402.

[0095] It should be noted that, as Figure 7 As shown, the distance between the extension section 451 and the expansion section 452 increases sequentially along the airflow path. On the one hand, this allows the air outlet 450 to better guide the airflow, and on the other hand, it increases the air volume of the volute air outlet 402.

[0096] like Figure 6 and Figure 7 As shown, the volute 400 includes a volute tongue 430, which is used to guide airflow. The volute tongue 430 is located at the connection between the main body 460 and the extension section 452, and protrudes from the inner wall of the volute 400. One side of the volute tongue 430 faces the centrifugal fan 500, and the other side of the volute tongue 430 faces the air outlet 402 of the volute.

[0097] like Figure 5 and Figure 6 As shown, the volute 400 includes a front panel 410, and the volute air inlet 401 is opened on the front panel 410. The front panel 410 is located near the front side of the housing 100.

[0098] In some embodiments, the opening direction of the volute air inlet 401 is generally oriented towards the front side of the housing 100.

[0099] like Figure 5 and Figure 6 As shown, the volute 400 includes a surrounding plate 420 connected to the front plate 410. The inner wall of the surrounding plate 420 extends along an extension curve, a spiral curve, a volute tongue curve, and an expansion curve 4521, so that the surrounding plate 420 and the front plate 410 together define a receiving cavity 404, an air outlet duct 403, and a volute air outlet 402. The inner wall of the surrounding plate 420 protrudes toward the interior of the volute 400 to define a volute tongue 430.

[0100] In some embodiments, the opening direction of the volute outlet 402 is generally oriented toward the top of the housing 100, so as to facilitate the flow of air from the inside of the volute 400 to the second cavity.

[0101] In some embodiments, the side of the enclosure 420 away from the front panel 410 is connected to the rear panel of the housing 100. The rear panel of the housing 100 is used to define and / or block the receiving cavity 404 and the air outlet duct 403 to limit the flow path of the airflow and ensure the stability and reliability of the airflow.

[0102] In existing technology, the windward surface of the volute tongue 430 is usually an arc surface, such as... Figure 8As shown, when the airflow passes through the windward side of the volute tongue 430, the transition of the volute tongue 430 towards the air outlet 402 of the volute is relatively large, which can easily block the airflow to a certain extent. This can cause some airflow to flow back into the receiving cavity 404, which can easily cause BPF noise, poor airflow and poor airflow performance, and can also easily lead to excessive pressure at the volute tongue 430.

[0103] If the windward surface of the 430 worm tongue is designed as an airfoil, such as Figure 9 As shown, when the airflow passes through the windward side of the volute tongue 430, the transition of the volute tongue 430 towards the air outlet 402 of the volute casing is relatively small. The airflow can flow along the side of the volute tongue 430 towards the air outlet 402 of the volute casing. The side of the volute tongue 430 towards the air outlet 402 of the volute casing has a good guiding effect on the airflow, and the airflow is not prone to backflow. However, the windward side of the volute tongue 430 is relatively sharp, and the airflow separation angle becomes smaller. When the airflow passes through the side of the volute casing 400 towards the centrifugal fan 500, the airflow is prone to local concentration, which makes the impact force of the airflow on the volute tongue 430 more concentrated and prone to producing abnormal noise.

[0104] Based on this, in this application, if Figure 10 As shown, the windward surface of the volute tongue 430 facing the centrifugal fan 500 is designed as an arc surface, and the windward surface of the volute tongue 430 facing the air outlet 402 of the volute is designed as an airfoil surface. The arc surface and the airfoil surface are smoothly transitioned. The arc surface is used to contact the airflow flowing towards the receiving cavity 404 to avoid local airflow concentration, which would cause flow loss or abnormal noise. The airfoil surface is used to guide the airflow out of the volute 400 to avoid airflow backflow.

[0105] Specifically, such as Figure 7 and Figure 11 As shown, the windward side of the volute tongue 430 is defined by a volute tongue curve; one end of the volute tongue curve is connected to the starting point of the spiral, and the other end of the volute tongue curve is connected to the end of the extension curve 4521 near the receiving cavity 404.

[0106] The volute tongue curve includes a first curve 431, which is set on the side of the volute tongue 430 facing the centrifugal fan 500; the first curve 431 is an arc curve.

[0107] The outer diameter of the blades of the centrifugal fan 500 is D, and the radius of the first curve 431 is R. R and D satisfy the following relationship: R≥0.07D, R≤0.15D, so that the airflow resistance is small when the airflow passes through the distance between the centrifugal fan 500 and the volute tongue 430 and the volute tongue 430 has a good guiding effect on the airflow.

[0108] If R < 0.07D, the distance between the windward side of the volute tongue 430 and the outer edge of the centrifugal fan 500 is small, resulting in greater airflow resistance.

[0109] If R>0.15D, the distance between the windward side of the volute tongue 430 and the outer edge of the centrifugal fan 500 is relatively large, and the volute tongue 430 has a poor guiding effect on airflow.

[0110] like Figure 11 As shown, the volute tongue curve includes a second curve 432, which is positioned on the side of the volute tongue 430 facing the volute outlet 402. The second curve 432 connects to the first curve 431, and the second curve 432 and the first curve 431 are tangent at the connection point. The end of the second curve 432 away from the first curve 431 connects to the end of the extended curve 4521 away from the volute outlet 402, and the extended curve 4521 and the second curve 432 are tangent at their connection point. It should be noted that the second curve 432 is an airfoil curve.

[0111] like Figure 12 As shown, a hypothetical curve 433 can be formed by extending the parameters of the first curve 431. Hypothetical curve 433 is set along the airflow path from the connection point of the second curve 432 and the first curve 431. The end of hypothetical curve 433 furthest from the first curve 431 is connected to the extended curve 4521. It should be noted that the parameters of the first curve 431 include, but are not limited to, the curvature, radius, and endpoint position of the first curve 431. It should also be noted that since the first curve 431 is a circular arc, the hypothetical curve 433 is also a circular arc.

[0112] like Figure 12 As shown, compared to the assumed curve 433, the second curve 432 is closer to the first curve 431. The transition at the connection between the second curve 432 and the first curve 431 is sharper than the transition at the connection between the assumed curve 433 and the first curve 431. Therefore, it is not easy for the airflow to generate backflow when it flows through the windward surface formed by the second curve 432.

[0113] By extending the first curve 431 to form the hypothetical curve 433, and comparing the second curve 432 with the hypothetical curve 433, it is possible to more intuitively and fully illustrate that the connection between the second curve 432 and the first curve 431 has a smaller transition, thereby making the windward surface formed by the second curve 432 have a better flow-guiding effect.

[0114] like Figure 12 and Figure 13 As shown, the second curve 432 can be extended to form a closed curve 700, which is a closed airfoil curve. The closed airfoil curve includes two ends, one end is roughly arc-shaped and is usually called the leading edge, and the other end is relatively sharp and is usually called the trailing edge. The thickness of the leading edge is usually greater than that of the trailing edge, and the maximum thickness of the airfoil curve is usually located near the leading edge. The maximum camber of the closed curve 700 is also located near the leading edge.

[0115] In this application, the second curve 432 is set on the closed curve 700 near the leading edge, and the curvature of the second curve 432 is greater than that of the first curve 431, so as to reduce the transition between the second curve 432 and the first curve 431 and avoid backflow when the airflow passes through the windward surface formed by the second curve 432.

[0116] like Figure 13 As shown, a closed curve 700 defines a central arc 701, which is located inside the closed curve 700. The central arc 701 defines a tangent 900 at its intersection with the volute tongue curve. A first plane 800 is defined by the length direction of the volute 400 and the opening direction of the volute inlet 401. The tangent 900 and the first plane 800 define a first included angle α.

[0117] like Figure 14 As shown, the blade is defined with a blade exit angle β. The first included angle α and the blade exit angle β of the centrifugal fan 500 satisfy the relationship: α+β=180°, so that the incoming flow direction at the volute tongue 430 is nearly tangent to the windward surface of the volute tongue 430 facing the air outlet 402 of the volute casing, thereby further reducing the wind resistance of the volute tongue 430 to the airflow.

[0118] If α+β>180°, when the airflow passes through the volute tongue 430, the windward side of the volute tongue 430 may interfere with the airflow. The airflow will exert pressure on the windward side of the volute tongue 430, which will easily increase the resistance of the volute tongue 430 to the airflow and reduce the guiding effect of the volute tongue 430 on the airflow.

[0119] If α+β<180°, when the airflow passes through the volute tongue 430, there is a distance between the airflow and the windward side of the volute tongue 430, which can easily reduce the guiding effect of the volute tongue 430 on the airflow.

[0120] like Figure 15 As shown, the closed curve 700 is an asymmetric airfoil curve. The line connecting the leading edge and the trailing edge is used as the dividing line to divide the closed curve 700 into two parts. That is, the closed curve 700 includes a first airfoil curve N and a second airfoil curve M. The camber of the first airfoil curve N is greater than the camber of the second airfoil curve M. At least part of the second curve 432 is located on the first airfoil curve N.

[0121] like Figure 13 As shown, the second airfoil curve M is positioned closer to the first curve 432 than the first curve 431. The curvature of the second airfoil curve M is greater than that of the first curve 431, so that the windward surface formed by the first curve 431 has a good guiding effect and guides the airflow to the receiving cavity 404.

[0122] By comparing the second airfoil curve M with the first curve 431, it can be more intuitively shown that the first curve 431 has a smaller curvature. In this application, the first curve 431 is defined to have a good guiding effect on the airflow facing the wind. Furthermore, the second curve 432 can be further defined, further defining the shape of the second curve 432 and the positional relationship between the second curve 432 and the first curve 431.

[0123] For ease of explanation, in this embodiment, the closed curve 700 is placed in a coordinate system for description.

[0124] like Figure 15 As shown, a planar coordinate system is established, which includes an x-axis set horizontally and a y-axis set vertically upward. The intersection of the x-axis and y-axis is the origin of the coordinate system.

[0125] The leading edge is located at the origin of the coordinate system, and the trailing edge is set towards the positive x-axis. The endpoints of the leading and trailing edges are located on the x-axis. The first airfoil N is located above the x-axis, and its two endpoints are set along and on the x-axis. The second airfoil M is located below the x-axis, and its two endpoints are set along and on the x-axis; the two ends of the second airfoil M along the x-axis are connected to the two ends of the first airfoil N along the x-axis. It should be noted that the mid-arc line 701 is located above the x-axis.

[0126] In this application, the curvature ym of the closed curve 700 satisfies the following relationship:

[0127]

[0128] Where m is the maximum curvature of the closed curve 700, p is the distance from the position of the maximum curvature on the closed curve 700 to the y-axis, and c is the straight-line distance from the leading edge to the trailing edge in the closed curve 700.

[0129] In this application, the thickness yt of the closed curve 700 satisfies the following relationship:

[0130]

[0131] Where t is the maximum thickness of the closed curve 700.

[0132] The first airfoil curve N satisfies the following relationship:

[0133] x N =xy t sinθ

[0134] y N =y m +y t cosθ

[0135] The second airfoil curve M satisfies the following relationship:

[0136] x M =x+y t sinθ

[0137] y M =y m -y t cosθ

[0138] Where θ satisfies the following relation:

[0139]

[0140] By defining the maximum curvature m and maximum thickness t of the closed curve 700, as well as the first airfoil curve N and the second airfoil curve M, the shape of the closed curve 700 is obtained, thereby obtaining the shape of the second curve 432.

[0141] For ease of description, the extended curve 4521 connected to the second curve 432 is called the first extended curve 4521a, and the extended curve 4521 connected to the hypothetical curve 433 is called the second extended curve 4521b.

[0142] Since the shape of the assumed curve 433 is different from that of the second curve 432, the shapes of the first extended curve 4521a and the second extended curve 4521b are also different.

[0143] Since the volute tongue 430 is connected to the extension section 452 on the side facing the air outlet 402 of the volute, in order to better guide the airflow, in this application, the extension section 452 is used to extend the volute tongue 430 on the side facing the air outlet 402 of the volute, that is, the windward surface of the connection between the extension section 452 and the volute tongue 430 is airfoil-shaped.

[0144] It can also be considered that, such as Figure 6 As shown, the extension section 452 is provided with a guide section 440. The guide section 440 is connected to the side of the volute tongue 430 facing the volute air outlet 402 and extends towards the volute air outlet 402 to guide the airflow to the volute air outlet 402. The windward surface of the guide section 440 is an airfoil to better guide the airflow.

[0145] It should be noted that the windward surface of the guide section 440 is defined by a guide curve 441, which is an extension curve 4521 or a part of the extension curve 4521. One end of the guide curve 441 extends toward the volute air outlet 402, and the other end of the guide curve 441 is connected to the end of the second curve 432 that is away from the first curve 431.

[0146] When the guide curve 441 is part of the extended curve 4521, it can be assumed that the windward surface of the extended section 452 at the connection with the volute tongue 430 is designed as an airfoil, and the rest is a non-airfoil.

[0147] When the guide curve 441 is the extension curve 4521, it can be assumed that the entire windward surface of the extension section 452 is designed as an airfoil, that is, the entire extension curve 4521 is an airfoil curve, so that the extension section 452 can have a better guiding effect on the airflow.

[0148] In this embodiment, the example of the flow guide curve 441 being a part of the expansion curve 4521 is used for illustration.

[0149] like Figure 16 As shown, the guide curve 441 and the second curve 432 are connected to form the third curve 702. The third curve 702 protrudes in a direction away from the volute tongue 430, so that the side of the volute tongue 430 facing the air outlet 402 of the volute and the guide part 440 can better guide the airflow.

[0150] The guide curve 441 and the second curve 432 can be combined to form an airfoil curve with the same parameters, so that the guide curve 441 and the second curve 432 can transition better, thereby allowing the windward side of the guide section 440 and the windward side of the volute tongue 430 facing the volute outlet 402 to transition better, thus enhancing the guiding effect on the airflow.

[0151] Guide curve 441 is an airfoil curve, and it lies on the first airfoil curve N; the third curve 702 is also an airfoil curve, and it lies on the closed curve 700.

[0152] like Figure 16 As shown, the line connecting the two endpoints of the third curve 702 is the chord length of the third curve 702. It should be noted that, in this embodiment, the chord length formed by connecting the two endpoints of the third curve 702 is the maximum chord length of the third curve 702. For ease of description, the line connecting the two endpoints of the third curve 702 is called the chord length line 703.

[0153] The connection point between the third curve 702 and the first curve 431 is point O. The third curve 702 has its maximum curvature at point A.

[0154] Point A has a projection point A′ on the chord line 703. The first straight line is formed by connecting points O and A′. The length L1 of the first straight line and the length L of the chord line 703 satisfy the following relationship: L1≥1 / 4L, L1≤1 / 2L.

[0155] If L1 < 1 / 4L, the transition between the guide section 440 and the volute tongue 430 towards the volute outlet 402 is too large, and the airflow is prone to backflow.

[0156] If L1>1 / 2L, the transition between the guide section 440 and the volute tongue 430 toward the air outlet 402 of the volute is smaller, and the guiding effect of the guide section 440 and the volute tongue 430 on the airflow is weaker.

[0157] like Figure 16 As shown, the third curve 702 has the maximum thickness at point B, and point B has a projection point B′ on the chord line 703. The second straight line is formed by connecting points O and B′. The length L2 of the second straight line and the length L of the chord line 703 satisfy the following relationship: L2≥0.12L, L2≤0.15L.

[0158] If L2 < 0.12L, then point B is set closer to the leading edge, and the transition of the third curve 702 at the connection between the guide section 440 and the volute tongue 430 is relatively large, making it easier for the airflow to generate backflow.

[0159] If L2>0.15L, the transition of the third curve 702 at the connection between the guide section 440 and the volute tongue 430 is relatively small. Although the airflow is not easy to generate backflow, the guiding effect of the guide section 440 and the volute tongue 430 on the side facing the air outlet 402 of the volute is relatively poor.

[0160] It should be noted that point B is positioned closer to the leading edge than point A.

[0161] It should be noted that the third curve 702 is a part of the closed curve 700, and the third curve 702 includes at least a portion of the first airfoil curve N.

[0162] Furthermore, it should be noted that the length of the chord line 703 is not necessarily equal to the length of the line connecting the leading and trailing edges of the closed curve 700, and the position of maximum curvature of the third curve 702 does not necessarily coincide with the position of maximum curvature of the closed curve 700. Only when the starting point of the second curve 432 coincides with the endpoint of the leading edge, and the endpoint of the guide curve 441 away from the second curve 432 coincides with the endpoint of the trailing edge, is the length of the chord line 703 equal to the length of the line connecting the leading and trailing edges of the closed curve 700.

[0163] like Figure 17 As shown, in this embodiment, a closed curve 700 generated by software is used. In this embodiment, the closed curve 700 uses the asymmetric combination NACA3315, meaning that the maximum camber m is 3% of the chord length, the maximum camber position P is at the 30% chord length line 703, and the maximum thickness t is 15% of the chord length line 703. Furthermore, other asymmetric airfoils can achieve similar effects, such as NACA2412 and NACA4315, which will not be described in detail here.

[0164] After verification, the multi-arc volute tongue 430 structure in this application can increase the air volume by about 2% compared with the conventional circular arc volute tongue 430 structure when the centrifugal fan speed is 500. The noise OA value is reduced by 0.5 dB(A) and the BPF peak noise is reduced by 2 dB(A) at the same air volume.

[0165] In the aforementioned indoor unit of the three-dimensional air conditioner, when the centrifugal fan 500 is operating, indoor air enters the centrifugal fan 500 through the air outlet 102 of the casing and the air inlet 401 of the volute. The air gains velocity due to the operation of the centrifugal fan 500. The airflow passes through the volute tongue 430 on the windward side facing the centrifugal fan 500 and flows along a spiral flow path within the receiving cavity 404. The airflow then passes through the volute tongue 430 on the windward side facing the air outlet 402 of the volute and flows along the extension section 452, allowing the airflow to be output into the second cavity. The windward side of the volute tongue 430 facing the centrifugal fan 500 is an arc surface, which can prevent localized airflow concentration, thus avoiding flow loss or abnormal noise. The windward side of the volute tongue 430 facing the air outlet 402 of the volute is an airfoil surface, which guides the airflow inside the volute and can prevent backflow, thereby reducing flow loss at the volute tongue 430.

[0166] In the aforementioned indoor unit of a three-dimensional air conditioner, the volute 430 is designed as a multi-segment airfoil structure, and the curve of the volute 430 is designed as a combination of conventional circular arcs and special airfoil profiles, with a smooth transition between the conventional circular arcs and special airfoil profiles. This makes the volute 430 a multi-segment airfoil structure, thereby improving the flow loss at the volute 430. As a result, the indoor unit of the three-dimensional air conditioner has good air outlet performance, large air volume, and small airflow loss.

[0167] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0168] For ease of explanation, the above description has been provided in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Various modifications and variations can be obtained based on the above teachings. The selection and description of the above embodiments are for the purpose of better explaining the principles and practical applications, thereby enabling those skilled in the art to better utilize the described embodiments and various different variations of embodiments suitable for specific use considerations.

Claims

1. A vertical air conditioner indoor unit, characterized in that, include: The housing has a first cavity and a second cavity defined inside it. The first cavity and the second cavity are distributed along the height direction of the housing, and the second cavity is located above the first cavity. The housing has an air inlet and an air outlet. The air inlet communicates with the first cavity, and the air outlet communicates with the second cavity. A heat exchanger is disposed within the second cavity; A centrifugal fan is located in the first cavity; when the centrifugal fan operates, it introduces outside air from the casing into the second cavity through the air inlet of the casing to exchange heat with the heat exchanger, and then outputs it to the room through the air outlet of the casing. A volute, disposed within the first cavity; the volute is located at the bottom of the housing; the volute has an air inlet and an air outlet, the air inlet communicating with the first cavity, and the air outlet communicating with the second cavity; the volute comprises: A volute tongue protrudes from the inner wall of the volute casing; one side of the volute tongue faces the centrifugal fan, and the other side faces the air outlet of the volute casing; the windward side of the volute tongue defines a volute tongue curve; the volute tongue curve includes: The first curve corresponds to the side of the volute tongue facing the centrifugal fan; The second curve is provided on the side of the volute tongue facing the air outlet of the volute shell; the second curve is connected to the first curve, and the second curve and the first curve are tangent at the connection point; The first curve extends to form a hypothetical curve, which is set along the airflow path from the connection point of the second curve and the first curve; the hypothetical curve and the first curve are circular arc curves, and the second curve is an airfoil curve; compared with the hypothetical curve, the second curve is set closer to the first curve.

2. The vertical air conditioner indoor unit according to claim 1, characterized in that, The second curve can be extended to form a closed curve, which is a closed airfoil curve. The curvature at the leading edge of the closed curve is greater than that of the first curve, and the second curve is set close to the leading edge of the closed curve.

3. The vertical air conditioner indoor unit according to claim 2, characterized in that, The closed curve defines a middle arc, and the middle arc defines a tangent at its intersection with the volute tongue curve; a first plane is defined by the length direction of the volute and the opening direction of the volute air inlet, and the tangent and the first plane define a first angle α, and the first angle α and the blade outlet angle β of the centrifugal fan satisfy the relationship: α + β = 180°.

4. The vertical air conditioner indoor unit according to claim 2, characterized in that, The inner wall of the volute is provided with a flow guide section, which is connected to the side of the volute tongue facing the air outlet of the volute and extends toward the air outlet of the volute to guide the airflow toward the air outlet of the volute; the windward surface of the flow guide section defines a flow guide curve, which is connected to the end of the second curve away from the first curve, and the flow guide curve and the second curve are tangent at the connection point of the two.

5. The vertical air conditioner indoor unit according to claim 4, characterized in that, The guiding curve and the second curve are connected to form a third curve. The connection point between the third curve and the first curve is point O. The third curve has the maximum curvature at point A. Point A has a projection point A′ on the chord of the third curve. A first straight line is formed by connecting points O and A′. The length L1 of the first straight line and the length L of the chord of the third curve satisfy the following relationship: L1≥1 / 4L, L1≤1 / 2L.

6. The vertical air conditioner indoor unit according to claim 4, characterized in that, The closed curve is an asymmetric airfoil curve. The closed curve is divided into a first airfoil curve and a second airfoil curve by the line connecting its leading edge and trailing edge. The camber of the first airfoil curve is greater than that of the second airfoil curve. At least a portion of the second airfoil curve lies on the first airfoil curve. The guide curve lies on the first airfoil curve.

7. The vertical air conditioner indoor unit according to claim 6, characterized in that, The second airfoil curve is positioned closer to the first airfoil curve, and the camber of the second airfoil curve is greater than that of the first airfoil curve.

8. The vertical air conditioner indoor unit according to claim 1, characterized in that, The outer diameter of the blades of the centrifugal fan is D, and the radius of the first curve is R. R and D satisfy the following relationship: R≥0.07D, R≤0.15D.

9. A vertical air conditioner indoor unit, characterized in that, include: The housing has a first cavity and a second cavity defined inside it. The first cavity and the second cavity are distributed along the height direction of the housing, and the second cavity is located above the first cavity. The housing has an air inlet and an air outlet. The air inlet communicates with the first cavity, and the air outlet communicates with the second cavity. A heat exchanger is disposed within the second cavity; A centrifugal fan is located in the first cavity; when the centrifugal fan operates, it introduces outside air from the casing into the second cavity through the air inlet of the casing to exchange heat with the heat exchanger, and then outputs it to the room through the air outlet of the casing. A volute is disposed within the first cavity; the volute is disposed at the bottom of the housing; the centrifugal fan is disposed inside the volute; the volute has an air inlet and an air outlet, the air inlet communicating with the first cavity, and the air outlet communicating with the second cavity; the volute includes: The volute tongue is located inside the volute and protrudes from the inner wall of the volute; one side of the volute tongue faces the centrifugal fan, and the other side of the volute tongue faces the air outlet of the volute. The windward surface of the volute tongue facing the centrifugal fan is an arc surface, and the windward surface of the volute tongue facing the air outlet of the volute casing is an airfoil surface, with the arc surface and the airfoil surface smoothly transitioning.

10. The vertical air conditioner indoor unit according to claim 9, characterized in that, The inner wall of the volute is provided with a flow guide, which is connected to the side of the volute tongue facing the air outlet of the volute and extends toward the air outlet of the volute; the windward surface of the flow guide smoothly transitions with the windward surface of the volute tongue facing the air outlet of the volute, and the windward surface of the flow guide is an airfoil.

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