Volute and total heat exchanger

Abstract

The application discloses a volute and a total heat exchanger, and relates to the technical field of air treatment equipment; the volute comprises a volute body and a volute tongue; a cavity for accommodating a centrifugal fan is defined in the volute body; a volute air outlet is formed in the volute body; the volute tongue is connected to the volute body; the volute tongue is arranged close to the volute air outlet; 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 volute tongue comprises a recessed part arranged on the side of the volute tongue towards the centrifugal fan; the recessed part is recessed in a direction away from the centrifugal fan; one end of the recessed part is connected to a protruding end of the volute tongue; the other end of the recessed part is connected to an inner wall of the volute body; the distance from the recessed part to the outer periphery of the centrifugal fan decreases in a direction away from the protruding end of the volute tongue, so that the gap between the volute tongue and the centrifugal fan decreases along the flow direction of the airflow in the volute; the volute can not only relieve the rotating noise of the centrifugal fan, but also reduce the loss of air volume.

Description

Technical Field

[0001] This application relates to the technical field of air handling equipment, and more particularly to a volute and a total heat exchanger. Background Technology

[0002] Centrifugal fans are an important component of total heat exchangers and are usually installed inside the volute. The main function of the volute is to effectively collect and guide the airflow leaving the centrifugal fan impeller, allowing it to flow smoothly towards the volute outlet. At the volute outlet, there is usually a volute tongue, which can guide the airflow and change its direction. Therefore, the design of the volute tongue has a significant impact on the aerodynamic performance (such as air volume and air pressure) and noise level of the entire unit.

[0003] Rotational noise is the primary noise source in centrifugal fan operation. Its generation mechanism lies in the broadband noise caused by the periodic pressure pulsations generated when the centrifugal fan strikes surrounding structures during rotation. Related technologies typically improve rotational noise by increasing the gap between the impeller and the volute. While this method does reduce rotational noise to some extent, it also increases the flow of rotating air returning to the impeller inlet through this gap, creating ineffective internal circulation and directly reducing the overall effective output air volume and air delivery efficiency of the unit.

[0004] In view of the above, this application is hereby submitted. Utility Model Content

[0005] To address the shortcomings of related technologies, this application provides a volute and a total heat exchanger. By providing a recess on the side of the volute tongue facing the centrifugal fan, the gap between the volute tongue and the centrifugal fan gradually decreases along the flow direction of the airflow inside the volute, thereby alleviating the rotational noise of the centrifugal fan and reducing the flow rate of the recovered air inside the volute, thus reducing air volume loss.

[0006] This application provides a volute, comprising: The volute body has a chamber inside which is defined to accommodate the centrifugal fan, and an air outlet is formed on the volute body. The volute tongue is connected to the volute body; the volute tongue is positioned near the air outlet of the volute body; 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 body; the volute tongue includes: The recessed part is located on the side of the volute tongue facing the centrifugal fan. The recessed part is recessed in a direction away from the centrifugal fan. One end of the recessed part is connected to the protruding end of the volute tongue, and the other end of the recessed part is connected to the inner wall of the volute body. The distance from the recess to the outer periphery of the centrifugal fan decreases along the direction away from the protruding end of the recess away from the volute tongue; the distance from the volute body to the centrifugal fan increases from the connection point between the volute body and the recess away from the recess.

[0007] In the technical solution, a recess is provided on the side of the volute tongue facing the centrifugal fan, and the recess is recessed in a direction away from the centrifugal fan to increase the distance between the volute tongue and the centrifugal fan. This results in a larger initial gap when the airflow inside the volute collides with the volute tongue, reducing the pressure pulsation value at the volute tongue and lowering the rotational noise of the centrifugal fan. By making the distance from the recess to the outer periphery of the centrifugal fan decrease from the protruding end of the recess away from the volute tongue, the distance from the connection between the recess and the volute body to the centrifugal fan is reduced, thereby reducing the flow rate of the recovered air inside the volute and reducing air volume loss.

[0008] In some embodiments of this application, the recessed portion is projected along the setting direction of the volute air inlet to form a first curve, the protruding end of the volute tongue is projected along the setting direction of the volute air inlet to form a second curve, and the inner wall of the volute body is projected along the setting direction of the volute air inlet to form a volute curve; the first curve protrudes in a direction away from the centrifugal fan; the starting end of the first curve is connected to the second curve, and the ending end of the first curve is connected to and tangent to the starting end of the volute curve; The distance from the starting end of the first curve to the outer periphery of the centrifugal fan is the first gap δ1, and the distance from the ending end of the first curve to the outer periphery of the centrifugal fan is the second gap δ2, where δ1≥δ2.

[0009] In the technical solution, by making the distance from the starting end of the first curve to the outer periphery of the centrifugal fan greater than the distance from the end of the first curve to the outer periphery of the centrifugal fan, the first gap is larger and the second gap is smaller. The larger first gap can reduce the pressure pulsation caused by the collision between the protruding end of the volute tongue and the rotating airflow, thereby reducing the rotational noise of the centrifugal fan. The smaller second gap can reduce the airflow recovered inside the volute, thereby reducing airflow loss.

[0010] In some embodiments of this application, the first gap δ1 and the second gap δ2 satisfy: δ1≤1.4δ2.

[0011] In the technical solution, by ensuring that the first gap δ1 and the second gap δ2 satisfy: δ1≤1.4δ2, the difference between the first gap and the second gap is kept within a reasonable range, so that the airflow can smoothly transition from the first gap to the second gap, avoiding eddies or turbulence caused by abrupt gap changes and reducing drag loss.

[0012] In some embodiments of this application, the first gap δ1 satisfies: δ1=12mm; the second gap δ2 satisfies: δ2=10mm.

[0013] In the technical solution, by making the first gap δ 12mm, the pressure pulsation generated by the collision between the protruding end of the volute tongue and the rotating airflow is reduced, thereby reducing the rotational noise of the centrifugal fan; by making the second gap δ2 10mm, the airflow recovered inside the volute is reduced, thereby reducing airflow loss.

[0014] In some embodiments of this application, the normal to the starting end of the first curve is defined as the first straight line, and the normal to the ending end of the first curve is defined as the second straight line. The second straight line intersects the first straight line to form an angle α, where α ≥ 15° and α ≤ 22°.

[0015] In the technical solution, the angle α formed by the normal at the starting end and the normal at the ending end of the first curve is ≥15° and ≤22°, so that the central angle of the first curve is 15° to 22°, avoiding an excessively long or short arc length. The gap between the volute tongue and the centrifugal fan is smaller than the gap between the inner wall of the volute body and the centrifugal fan. If the arc length of the first curve is too long, the path of airflow through the smaller gap between the volute tongue and the centrifugal fan increases, potentially leading to a larger frictional contact area between the airflow and the volute tongue wall, resulting in greater frictional resistance loss. Airflow separation is also more likely, generating additional vorticity and flow loss, reducing efficiency and potentially introducing new noise sources. If the arc length of the first curve is too short, the vorticity at the volute tongue cannot be sufficiently transferred to the bottom of the volute tongue, causing a significant accumulation of vorticity near the air outlet. This makes it difficult to suppress noise at its source, and insufficient vorticity at the bottom also eliminates the obstruction effect on the transmission path, significantly weakening the noise reduction effect.

[0016] In some embodiments of this application, the radius R1 of the first curve and the outer diameter R2 of the centrifugal fan satisfy: R1≥R2, R1≤1.125R2.

[0017] In the technical solution, by making the ratio of the radius R1 of the first curve to the outer diameter R2 of the centrifugal fan greater than or equal to 1 and less than or equal to 1.125, the curvature of the first curve and the size of the centrifugal fan are reasonably matched, so that the length of the first flow channel is within a suitable range. This avoids the situation where the vortex at the volute tongue cannot be effectively transferred to the bottom of the volute tongue due to insufficient length of the first flow channel, causing the vortex to accumulate in the volute tongue area near the air outlet of the volute, making it difficult to reduce noise at the source. It also prevents the frictional contact area between the airflow and the windward side of the recessed part from increasing due to the first flow channel being too long, resulting in additional frictional resistance loss. At the same time, it reduces the risk of airflow separation and vortex formation due to prolonged confinement.

[0018] In some embodiments of this application, the radius R1 of the first curve and the inner diameter R3 of the volute curve satisfy: R1≥1.27R2, R1≤1.665R2.

[0019] In the technical solution, by making the ratio of the radius R1 of the first curve to the inner diameter R3 of the volute curve greater than or equal to 1.27 and less than or equal to 1.665, the dimensional relationship between the first curve and the volute curve is reasonably controlled, ensuring a smoother transition of airflow between the first and second flow channels, reducing flow resistance and pressure fluctuations, and ensuring efficient conversion of airflow kinetic energy to static pressure energy, thereby improving the aerodynamic efficiency and operational stability of the centrifugal fan.

[0020] In this technical solution, by limiting the curvature of the volute curve to be greater than that of the first curve, the airflow between the end of the recess and the volute body is ensured to be more in line with aerodynamic principles. The greater curvature of the volute curve allows the airflow to quickly turn and accelerate into the volute channel after leaving the volute tongue region, reducing flow separation and energy loss. Simultaneously, it suppresses turbulence during vortex diffusion at the bottom of the volute tongue, enhancing the efficiency of airflow convergence towards the outlet, thereby increasing airflow volume and reducing turbulent noise.

[0021] In some embodiments of this application, the distance from the volute curve to the outer periphery of the centrifugal fan is δ3, where δ3 ≥ δ2.

[0022] In the technical solution, the distance from the volute curve to the outer periphery of the centrifugal fan is greater than or equal to the distance from the end of the first curve to the centrifugal fan, so that a gradually expanding channel is formed after the end of the concave part, avoiding the generation of reverse pressure gradient and flow separation due to sudden expansion of airflow, ensuring the stability of airflow, and providing diffusion space for the vortex transmitted at the bottom of the volute tongue, ultimately achieving the dual optimization of reducing airflow loss and suppressing low- and mid-frequency noise.

[0023] In addition, this application also provides a total heat exchanger, comprising: The casing has an air inlet and an air outlet. The heat exchange core is located inside the housing and is used to exchange heat with the air passing through it. The aforementioned volute is located inside the housing and on the leeward side of the heat exchange core; the volute outlet is connected to the housing outlet, and the volute inlet is connected to the interior of the volute. Centrifugal fan, the centrifugal fan is located inside the volute.

[0024] In the technical solution, by configuring the above-mentioned volute in the total heat exchanger, not only can the vortex accumulation and pressure pulsation at the volute tongue be reduced during the operation of the centrifugal fan, thus suppressing rotational noise from the source, but also the airflow velocity and backflow inside the volute can be reduced, improving air supply efficiency and airflow stability, making the airflow distribution on the surface of the heat exchange core more uniform, enhancing the temperature and humidity exchange efficiency, and increasing the total heat exchange performance.

[0025] In the above embodiments, a volute and total heat exchanger, by providing a recessed portion on the side of the volute tongue facing the centrifugal fan, gradually reduces the gap between the volute tongue and the centrifugal fan along the flow direction of the airflow inside the volute. This reduces pressure pulsation caused by the collision between the upper region of the volute tongue and the rotating airflow, lowers the fan rotation noise, reduces vortex accumulation at the volute tongue, and transfers some vortex to the bottom of the volute tongue, thereby reducing noise caused by vortex accumulation at the outlet from the noise source. Furthermore, the smaller gap between the bottom region of the volute tongue and the centrifugal fan reduces the airflow recovered inside the volute, lowers airflow loss, and the vortex at the bottom of the volute tongue is obstructed by the outer wall of the volute during noise transmission, further reducing noise. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of one embodiment of the volute of this application; Figure 2 This is a structural schematic diagram of another embodiment of the volute of this application from another angle; Figure 3 for Figure 2 Sectional view of AA; Figure 4 This is a schematic diagram of the structure of the volute housing in one embodiment of this application when a centrifugal fan is installed; Figure 5 This is a schematic diagram of the volute casing of this application from another angle when a centrifugal fan is installed; Figure 6 This is a schematic diagram of the first curve and the volute curve in one embodiment of the volute of this application; Figure 7 This is a schematic outline diagram of the volute casing in one embodiment of this application after a centrifugal fan has been installed; Figure 8 for Figure 7 Enlarged view of a section at point A in the middle; Figure 9 This is a schematic diagram showing the dimensions of the first curve in one embodiment of the volute of this application; Figure 10 This is a schematic diagram of the structure of one embodiment of the total heat exchanger of this application; Figure 11 This is a schematic diagram of the internal structure of one embodiment of the total heat exchanger of this application.

[0027] In the diagram, 100 is the volute; 200 is the centrifugal fan; 300 is the casing; and 400 is the heat exchange core. 101. Volute air inlet; 102. Volute air outlet; 103. First flow channel; 104. Second flow channel; 110. Volute body; 120. Volute tongue; 121. Depression; 122. Protrusion; 1211, First curve; 1212, First straight line; 1213, Second straight line; 1101. Volute curve; 301. Air inlet of the casing; 302. Air outlet of the casing. Detailed Implementation

[0028] 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.

[0029] 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.

[0030] 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.

[0031] The terms “comprising” and “having”, and any variations thereof, are intended to cover but not exclude inclusion, 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.

[0032] like Figures 1-5 In one specific embodiment of the volute 100 of this application, the volute 100 includes a volute body 110, and the volute body 110 has a chamber defined inside for accommodating the centrifugal fan 200.

[0033] A volute air inlet 101 is formed on the volute body 110, and air enters the interior of the volute body 110 through the volute air inlet 101.

[0034] like Figure 1 and Figure 5 As shown, a volute air outlet 102 is formed on the volute body 110, and air is output from the volute body 110 through the volute air outlet 102.

[0035] like Figure 1As shown, the volute 100 includes a volute tongue 120, which protrudes from the inner wall of the volute body 110; the volute tongue 120 is located near the air outlet 102 of the volute; the volute tongue 120 has two opposing sides along its protruding direction, wherein one side of the volute tongue 120 faces the centrifugal fan 200, and the other side of the volute tongue 120 faces the air outlet 102 of the volute.

[0036] For ease of description, the part where the volute tongue 120 connects to the volute body 110 is called the bottom region of the volute tongue 120, and the part of the volute tongue 120 that protrudes from the inner wall of the volute body 110 is called the upper region of the volute tongue 120.

[0037] like Figure 3 and Figure 4 As shown, the volute tongue 120 includes a protruding end 122, which is located in the upper region of the volute tongue 120 and is disposed away from the volute body 110 along the protruding direction of the volute tongue 120.

[0038] like Figure 3 and Figure 4 As shown, the volute tongue 120 includes a recessed portion 121, which is located in the bottom region of the volute tongue 120. The recessed portion 121 is provided on the side of the volute tongue 120 facing the centrifugal fan 200. The recessed portion 121 is recessed in a direction away from the centrifugal fan 200. The recessed portion 121 is generally arranged along the protruding direction of the volute tongue 120. One end of the recessed portion 121 is connected to the protruding end 122, and the other end of the recessed portion 121 is connected to the inner wall of the volute body 110.

[0039] When the airflow passes through the recess 121, the airflow first passes through the connection between the recess 121 and the protrusion 122, and then passes through the connection between the recess 121 and the volute body 110.

[0040] In some embodiments, the recess 121 is a recessed curved surface provided on the side of the volute tongue 120 facing the centrifugal fan 200.

[0041] like Figure 8 As shown, a first flow channel 103 is defined between the recess 121 and the outer periphery of the centrifugal fan 200. The distance from the recess 121 to the outer periphery of the centrifugal fan 200 is the width of the first flow channel 103. The airflow flows from the connection between the recess 121 and the protrusion 122 to the connection between the recess 121 and the volute body 110 within the first flow channel 103.

[0042] The width of the first flow channel 103 decreases from the recess 121 away from the protruding end 122, so that when the airflow just flows through the recess 121, the gap between the recess 121 and the centrifugal fan 200 is larger, which can reduce the pressure pulsation value at the volute tongue 120 and reduce the rotational noise of the centrifugal fan 200; when the airflow is about to leave the recess 121, the gap between the recess 121 and the centrifugal fan 200 is smaller, which can reduce the flow rate of the recovered air inside the volute 100 and reduce the air volume loss.

[0043] like Figure 7 As shown, a second flow channel 104 is defined between the outer periphery of the centrifugal fan 200 and the inner wall of the volute body 110, and the distance between the outer periphery of the centrifugal fan 200 and the volute body 110 is the width of the second flow channel 104.

[0044] It should be noted that one end of the second flow channel 104 is connected to the first flow channel 103, and the other end of the second flow channel 104 is connected to the volute air outlet 102. The airflow flows from the connection between the volute body 110 and the recess 121 to the volute air outlet 102 within the second flow channel 104.

[0045] The width of the second flow channel 104 increases from the connection between the volute body 110 and the recess 121 in a direction away from the recess 121, so as to adapt to the airflow characteristics of the centrifugal fan 200 and optimize the energy conversion efficiency.

[0046] When the centrifugal fan 200 is working, the airflow is thrown out from the impeller of the centrifugal fan 200 and diffuses radially. The flow velocity gradually decreases as the flow path lengthens. The gradually increasing width of the second flow channel 104 can match the space requirements after the airflow diffuses, avoiding airflow congestion, eddy currents, or impact losses caused by the second flow channel 104 being too narrow. At the same time, it can realize the smooth conversion of kinetic energy to static pressure energy, reduce pressure fluctuations, improve wind pressure output efficiency, and reduce the frictional resistance between the airflow and the inner wall of the volute body 110, reducing energy loss, and ultimately achieving a more efficient and stable air delivery effect.

[0047] like Figure 6 and Figure 8 As shown, the connection between the recessed portion 121 and the inner wall of the volute body 110 is smooth to ensure the smoothness and continuity of airflow and to avoid airflow separation, eddies or local turbulence caused by abrupt structural changes such as sharp corners or steps at the connection.

[0048] like Figure 6 As shown, the recessed portion 121 is projected along the setting direction of the volute air inlet 101 to form a first curve 1211, and the first curve 1211 protrudes in a direction away from the centrifugal fan 200.

[0049] The protruding end 122 is projected along the setting direction of the volute air inlet 101 to form a second curve, and the second curve is connected to the starting end of the first curve 1211.

[0050] The inner wall of the volute body 110 is projected along the direction of the volute inlet 101 to form a volute curve 1101. The starting end of the volute curve 1101 is connected to and tangent to the end of the first curve 1211. The volute curve 1101 and the first curve 1211 transition smoothly.

[0051] like Figure 8 As shown, the distance from the starting end of the first curve 1211 to the outer periphery of the centrifugal fan 200 is the first gap δ1, and the distance from the ending end of the first curve 1211 to the outer periphery of the centrifugal fan 200 is the second gap δ2, where δ1 ≥ δ2, so that the first gap δ1 is larger and the second gap δ2 is smaller. A larger first gap δ1 can reduce the pressure pulsation generated by the collision between the protruding end 122 of the volute tongue 120 and the rotating airflow, thus reducing the rotational noise of the centrifugal fan 200; a smaller second gap δ2 can reduce the airflow recovered inside the volute 100, thereby reducing airflow loss.

[0052] If δ1 < δ2, although the rotational noise of the centrifugal fan 200 can be improved, the rotational airflow inside the volute 100 will increase, which will reduce the airflow output from the volute outlet 102.

[0053] The first gap δ1 and the second gap δ2 satisfy: δ1≥δ2, δ1≤1.4δ2, so that the difference between the first gap and the second gap is within a reasonable range, so that the first flow channel 103 contracts gently, thereby allowing the airflow to smoothly transition from the first gap to the second gap, avoiding the generation of vortices or turbulence due to the sudden change in the width of the first flow channel 103, and reducing drag loss.

[0054] If δ1 > 1.4δ2, the first flow channel 103 will contract too quickly, and the airflow velocity will suddenly increase when flowing through the first flow channel 103. This will easily cause local turbulence and airflow separation. The airflow that was originally flowing smoothly in the first gap will form vortices or impact the inner wall of the volute body 110 due to the sudden narrowing of the first flow channel 103. This will not only increase the flow resistance of the airflow and cause additional energy loss, but also lead to increased pressure pulsation. This may offset the noise reduction effect brought by the larger first gap, and even generate new aerodynamic noise. At the same time, the excessively rapid contraction may also disrupt the smoothness of the conversion of kinetic energy to static pressure energy, affect the stability of wind pressure output, and ultimately reduce the overall aerodynamic efficiency of the centrifugal fan 200.

[0055] In some embodiments, the first gap δ1 satisfies: δ1=12mm, so as to reduce the pressure pulsation generated by the collision between the protruding end 122 of the volute tongue 120 and the rotating airflow, and reduce the rotational noise of the centrifugal fan 200.

[0056] In some embodiments, the second gap δ2 satisfies: δ2=10mm, so as to reduce the airflow recovered inside the volute 100, thereby reducing airflow loss.

[0057] like Figure 9 As shown, the normal to the starting end of the first curve 1211 is defined as the first straight line 1212, and the normal to the ending end of the first curve 1211 is defined as the second straight line 1213. The second straight line 1213 intersects the first straight line 1212 at an angle α, where α ≥ 15° and α ≤ 22°. This ensures that the arc length of the first curve 1211 is within a reasonable range, and that the length of the first flow channel 103 is also within a reasonable range. This ensures that the airflow obtains a sufficient and appropriate flow path within the first flow channel 103, thus avoiding the problems caused by the first flow channel... The length of 103 is insufficient, which cannot effectively transfer the vortex at the volute tongue 120 to the bottom of the volute tongue 120. This causes the vortex to accumulate in the area of ​​the volute tongue 120 near the air outlet 102 of the volute, making it difficult to reduce noise at the source. It can also prevent the airflow from flowing in the narrow first flow channel 103 due to the excessive length of the first flow channel 103, which would increase the frictional contact area with the windward side of the recess 121 and generate additional frictional resistance loss. At the same time, it reduces the risk of airflow separation and vortex formation due to long-term confinement.

[0058] It should be noted that a reasonable arc length of the first curve 1211 can be used to coordinate the smooth transition between the first gap δ1 and the second gap δ2, ensuring the smooth flow of air from the first gap to the second gap, maintaining the stability of the conversion of kinetic energy to static pressure energy, and ultimately achieving a balance between reducing noise, reducing air volume loss, and improving aerodynamic efficiency.

[0059] If α > 22°, the arc length of the first curve 1211 is too long, that is, the length of the first flow channel 103 is too large. The width of the first flow channel 103 is smaller than the width of the second flow channel 104. The airflow flows in the narrower first flow channel 103 for a long time, which may increase the frictional contact area between the airflow and the windward side of the recess 121, resulting in greater frictional resistance loss. The airflow is also prone to flow separation, generating additional vorticity and flow loss, reducing efficiency and possibly causing new noise sources.

[0060] If α < 15°, the arc length of the first curve 1211 is too short, that is, the length of the first flow channel 103 is too short. The first flow channel 103 cannot fully transfer the vortex at the volute tongue 120 to the bottom of the volute tongue 120, resulting in a large amount of vortex accumulating at the volute tongue 120 near the air outlet 102 of the volute, making it difficult to suppress noise from the source.

[0061] In some embodiments, the first curve 1211 is a circular arc curve with a central angle of 15° to 22°.

[0062] like Figure 7As shown, the radius R1 of the first curve 1211 and the outer diameter R2 of the centrifugal fan 200 satisfy: R1≥R2, R1≤1.125R2. By reasonably matching the curvature of the first curve 1211 with the size of the centrifugal fan 200, the length of the first flow channel 103 is within a suitable range. This avoids the situation where the length of the first flow channel 103 is insufficient, which would prevent the vorticity at the volute tongue 120 from being transferred to the bottom of the volute tongue 120, causing the vorticity to accumulate in the volute tongue 120 area near the air outlet 102 of the volute, making it difficult to reduce noise at the source. It also prevents the frictional contact area between the airflow and the windward side of the recess 121 from increasing when the airflow flows in the narrow first flow channel 103 due to the excessive length of the first flow channel 103, resulting in additional frictional resistance loss. At the same time, it reduces the risk of airflow separation and vorticity formation due to long-term confinement.

[0063] If R1 > 1.125 R2, then the arc length of the first curve 1211 is too long, that is, the length of the first flow channel 103 is too large. The width of most areas of the first flow channel 103 is usually smaller than the width of most areas of the second flow channel 104. If the airflow flows in the narrower first flow channel 103 for a long time, it may cause the frictional contact area between the airflow and the windward side of the recess 121 to increase, resulting in greater frictional resistance loss. The airflow is also prone to flow separation, generating additional vorticity and flow loss, reducing efficiency and potentially causing new noise sources.

[0064] If R1 < R2, the arc length of the first curve 1211 is too short, that is, the length of the first flow channel 103 is too short. The first flow channel 103 cannot fully transfer the vortex at the volute tongue 120 to the bottom of the volute tongue 120, resulting in a large amount of vortex accumulating at the volute tongue 120 near the air outlet 102 of the volute, making it difficult to suppress noise from the source.

[0065] like Figure 7 As shown, the radius R1 of the first curve 1211 and the inner diameter R3 of the volute curve 1101 satisfy: R1≥1.27 R3, R1≤1.665 R3. By reasonably controlling the dimensional relationship between the first curve 1211 and the volute curve 1101, the transition of airflow between the first flow channel 103 and the second flow channel 104 is made smoother, reducing flow resistance and pressure fluctuations, while ensuring the efficient conversion of airflow kinetic energy to static pressure energy, thereby improving the aerodynamic efficiency and operational stability of the centrifugal fan 200.

[0066] If R1 > 1.665 R3, the radius of the first curve 1211 is too large, which reduces the adaptability of the flow channel shape to the volute curve 1101. The connection between the first flow channel 103 and the second flow channel 104 is prone to airflow separation, eddies or local turbulence due to structural abruptness. To ensure the continuity of airflow, the airflow is prone to congestion or energy loss in the second flow channel 104. If R1 < 1.27 R3, the radius of the first curve 1211 is too small, causing a sudden change in curvature. The connection between the first flow channel 103 and the second flow channel 104 is prone to airflow separation, eddies or local turbulence due to the abrupt structure, which may affect the continuity of airflow.

[0067] The curvature of the volute curve 1101 is greater than that of the first curve 1211 to ensure that the airflow between the end of the recess 121 and the main body of the volute 100 is more in line with aerodynamic laws. The larger curvature of the volute curve 1101 allows the airflow to quickly turn and accelerate into the flow channel of the volute 100 after leaving the volute tongue 120 area, reducing flow separation and energy loss; at the same time, it can also suppress the turbulence during the diffusion of vortices at the bottom of the volute tongue 120, enhance the convergence efficiency of the airflow to the volute outlet 102, thereby increasing the air volume and reducing turbulent noise.

[0068] like Figure 8 As shown, the distance from the volute curve 1101 to the outer periphery of the centrifugal fan 200 is δ3, where δ3 ≥ δ2, so that the width of the second flow channel 104 is less than or equal to the width at the connection between the first flow channel 103 and the second flow channel 104. This allows the second flow channel 104 to form a gradually expanding channel after the end of the recess 121, avoiding the generation of adverse pressure gradients and flow separation due to sudden expansion of the airflow, ensuring the stability of the airflow, and providing diffusion space for the vorticity transmitted at the bottom of the volute tongue 120. Ultimately, this achieves the dual optimization of reducing airflow loss and suppressing low- and mid-frequency noise.

[0069] The aforementioned volute 100, by providing a recessed portion 121 on the side of the volute tongue 120 facing the centrifugal fan 200, gradually reduces the gap between the volute tongue 120 and the centrifugal fan 200 along the flow direction of the airflow inside the volute 100. This reduces pressure pulsation caused by the collision between the upper region of the volute tongue 120 and the rotating airflow, thereby reducing the fan's rotational noise and reducing vortex accumulation at the volute tongue 120. Some of the vortex is transferred to the bottom of the volute tongue 120, reducing the noise caused by vortex accumulation at the outlet from the noise source. Furthermore, the smaller gap between the bottom region of the volute tongue 120 and the centrifugal fan 200 reduces the airflow recovered inside the volute 100, reducing airflow loss. Additionally, the vortex at the bottom of the volute tongue 120 is obstructed by the outer wall of the volute 100 during noise transmission, further reducing noise.

[0070] Based on the aforementioned volute 100, such as Figure 10 and Figure 11 As shown, this application also provides a total heat exchanger, which includes a housing 300 for forming the overall appearance of the total heat exchanger.

[0071] An air inlet 301 is formed on the housing 300. The air inlet 301 is located on the outer peripheral wall of the housing 300, and air enters the interior of the housing 300 through the air inlet 301.

[0072] The housing 300 has a housing air outlet 302, which is located on the outer peripheral wall of the housing 300. Air inside the housing 300 is output to the outside of the housing 300 through the housing air outlet 302.

[0073] In some embodiments, the housing air outlet 302 and the housing air inlet 301 are provided on opposite side peripheral walls of the housing 300.

[0074] The total heat exchanger includes a heat exchange core 400, which is located inside the housing 300 and is used to exchange heat with the air passing through the heat exchange core 400.

[0075] The total heat exchanger includes a centrifugal fan 200, which is located inside the volute 100.

[0076] The total heat exchanger includes the aforementioned volute 100, which is located inside the housing 300 and is used to house the centrifugal fan 200. The volute air inlet 101 is connected to the housing air inlet 301 so that the air entering the housing 300 can enter the volute 100 through the volute air inlet 101.

[0077] The volute air outlet 102 is connected to the housing air outlet 302 so that the air inside the volute 100 can be output to the outside of the housing 300 through the housing air outlet 302.

[0078] During the operation of the total heat exchanger, under the action of the centrifugal fan 200, indoor air enters the interior of the casing 300 through the casing air inlet 301 and comes into contact with the heat exchange core 400. After heat exchange through the heat exchange core 400, the air is finally discharged to the outside through the casing air outlet 302.

[0079] The configuration of the volute 100 in the total heat exchanger not only reduces the vortex accumulation and pressure pulsation at the volute tongue 120 during the operation of the centrifugal fan 200, thus suppressing rotational noise at the source, but also reduces the airflow velocity and backflow inside the volute 100, improves the air supply efficiency and airflow stability, makes the airflow distribution on the surface of the heat exchange core 400 more uniform, enhances the temperature and humidity exchange efficiency, and increases the total heat exchange performance.

[0080] It should be noted that the aforementioned volute 100 can also be applied to equipment such as indoor units of vertical air conditioners; the specific structure of the total heat exchanger is existing technology in this field and will not be described in detail here.

[0081] The aforementioned volute 100 and total heat exchanger have at least the following advantages: 1. The variable gap design of the first flow channel 103 reduces the accumulation and concentrated distribution of vorticity at the protruding end 122. Some of the vorticity concentrated at the protruding end 122 is transferred through the first flow channel 103 and dispersed to the bottom area of ​​the volute tongue 120, reducing the concentration of vorticity at the volute outlet 102, thereby suppressing the generation of some noise at the source of noise.

[0082] 2. A recess 121 is provided on the side of the volute tongue 120 facing the centrifugal fan 200. This allows some of the vorticity to be guided and concentrated in the bottom region of the volute tongue 120. This vorticity concentrated at the bottom of the volute tongue 120 and its accompanying flow structure physically add an extra "barrier" or obstruction to the area inside the volute 100 near the volute tongue 120. When noise propagates outward along the volute body 110, this "barrier" formed by vorticity can interfere with and absorb some of the sound wave energy, increasing the acoustic damping along the noise propagation path, thereby effectively attenuating the outwardly radiated noise.

[0083] 3. Increase the width of the first flow channel 103 at the starting end, that is, increase the first gap δ1, so that the airflow can flow more smoothly through the protruding end 122, reduce the violent pressure pulsation generated when the airflow hits the protruding end 122, and reduce the noise caused therefrom.

[0084] 4. Reducing the width of the first flow channel 103 at the end, i.e. reducing the second gap δ2, can prevent secondary flow and backflow of airflow inside the volute 100, reduce the ineffective airflow from the protruding end 122 to the volute air inlet 101, reduce leakage loss inside the volute 100, improve the aerodynamic efficiency of the centrifugal fan 200, and reduce airflow loss.

[0085] 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.

[0086] 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 volute, characterized in that, include: The volute body has a chamber defined inside for accommodating a centrifugal fan, and a volute air outlet is formed on the volute body. A volute tongue, connected to the volute body; the volute tongue is positioned near the air outlet of the volute body; 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 body; the volute tongue includes: The recessed portion is located on the side of the volute tongue facing the centrifugal fan, and the recessed portion is recessed in a direction away from the centrifugal fan. One end of the recessed portion is connected to the protruding end of the volute tongue, and the other end of the recessed portion is connected to the inner wall of the volute body. The distance from the recess to the outer periphery of the centrifugal fan decreases along the direction away from the protruding end of the recess away from the volute tongue; the distance from the volute body to the centrifugal fan increases from the connection point between the volute body and the recess away from the recess.

2. The volute according to claim 1, characterized in that, The recessed portion is projected along the direction of the volute air inlet to form a first curve, the protruding end of the volute tongue is projected along the direction of the volute air inlet to form a second curve, and the inner wall of the volute body is projected along the direction of the volute air inlet to form a volute curve; the first curve protrudes in a direction away from the centrifugal fan; the starting end of the first curve is connected to the second curve, and the ending end of the first curve is connected to and tangent to the starting end of the volute curve; The distance from the starting end of the first curve to the outer periphery of the centrifugal fan is the first gap δ1, and the distance from the ending end of the first curve to the outer periphery of the centrifugal fan is the second gap δ2, wherein δ1≥δ2.

3. The volute according to claim 2, characterized in that, The first gap δ1 and the second gap δ2 satisfy the condition: δ1≤1.4δ2.

4. The volute according to claim 2, characterized in that, The first gap δ1 satisfies: δ1=12mm; the second gap δ2 satisfies: δ2=10mm.

5. The volute according to claim 2, characterized in that, The normal to the starting end of the first curve is defined as the first straight line, and the normal to the ending end of the first curve is defined as the second straight line. The second straight line intersects the first straight line to form an angle α, where α ≥ 15° and α ≤ 22°.

6. The volute according to claim 2, characterized in that, The radius R1 of the first curve and the outer diameter R2 of the centrifugal fan satisfy the following conditions: R1≥R2, R1≤1.125R2.

7. The volute according to claim 2, characterized in that, The radius R1 of the first curve and the inner diameter R3 of the volute curve satisfy: R1≥1.27R2, R1≤1.665R2.

8. The volute according to claim 2, characterized in that, The curvature of the volute curve is greater than that of the first curve.

9. The volute according to claim 2, characterized in that, The distance from the volute curve to the outer periphery of the centrifugal fan is δ3, where δ3 ≥ δ2.

10. A total heat exchanger, characterized in that, include: A housing, on which an air inlet and an air outlet are formed; A heat exchange core is disposed inside the housing and is used to exchange heat with the air passing through the heat exchange core; The volute as described in any one of claims 1-9 is disposed inside the housing and located on the leeward side of the heat exchange core; the air outlet of the volute is connected to the air outlet of the housing and the air inlet of the volute is connected to the interior of the volute. A centrifugal fan, which is located inside the volute.

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