A centrifugal fan volute profile design method and centrifugal fan

Abstract

The present application provides a centrifugal fan volute profile design method and a centrifugal fan, and relates to the technical field of centrifugal fans. Under the condition of limiting the external dimensions of the volute and the outer diameter of the impeller, the control variable method is adopted, and one of the structural parameters is changed each time according to a certain solution order, and the other parameter values ​​remain unchanged. The target parameters including the optimal structural parameter values ​​corresponding to the optimal values ​​of the air volume and / or noise are solved, and then the optimal solution of the volute profile is designed. The parameter values ​​include the radius of the volute tongue, the shortest distance of the volute throat, the width of the volute outlet, multiple opening values, and the vertical distance between the position of the opening value closest to the volute outlet and the volute outlet. Using the design method of the present application, it is possible to solve the optimal solution of the initial volute profile by using the control variable method under limited size conditions and in a certain solution order, so as to design a fan with the maximum air volume or the minimum noise.

Description

Technical Field

[0001] This application belongs to the field of centrifugal fan technology, and in particular relates to a centrifugal fan volute profile design method and a centrifugal fan. Background Technology

[0002] A centrifugal fan is a machine that uses input mechanical energy to increase gas pressure and discharge gas. It utilizes a high-speed rotating impeller to accelerate gas, providing ventilation and accelerating air circulation. With the improvement of people's living standards and the upgrading of consumer demands, the quality requirements for household appliances are becoming increasingly higher. Centrifugal fans are typically installed inside the air intake box of range hoods or air conditioners, and have advantages such as small size, low speed, large flow coefficient, high pressure coefficient, and low noise. Currently, high efficiency and low noise have become the main design goals of household appliances, and as a core power component, the overall performance of household appliances is significantly affected by the structural characteristics of its various components.

[0003] The volute of a centrifugal fan is a stationary working component, and its shape determines its performance. Due to the internal dimensions of the electrical intake box, the overall dimensions of the volute profile are also limited to a certain range. In related technologies, volute profile design methods include the Archimedean spiral method, the equilateral element method, and the scalene element method. While the Archimedean spiral method incorporates the concept of opening design, it cannot freely control the circumferential distribution of the volute opening. Therefore, controlling the circumferential distribution of the volute opening, and thus designing a reasonable volute flow channel, is crucial for developing the ultimate performance of centrifugal fans within limited dimensions.

[0004] Centrifugal fan impellers rely on centrifugal force to do work. This centrifugal force is directly proportional to the impeller diameter and rotational speed; larger impellers have greater work capacity. However, due to factors such as motor load and impeller rotational stability, the impeller outer diameter is generally limited to a certain size. Therefore, in the design of centrifugal fans, the volute profile is constrained by both the internal dimensions of the inlet box and the impeller outer diameter. Under these conditions, designing a reasonable volute profile is of paramount importance for improving the aerodynamic performance and reducing noise of centrifugal fans. Summary of the Invention

[0005] In view of the above problems, this application provides a centrifugal fan volute profile design method and a centrifugal fan to solve the technical problem of how to design a reasonable volute profile under the constraints of impeller outer diameter and air inlet box size.

[0006] This application provides a method for designing the profile of a centrifugal fan volute. The centrifugal fan includes a volute and an impeller disposed inside the volute. The method includes:

[0007] Under defined conditions, determine the external dimensions of the volute and the outer diameter D of the impeller;

[0008] Assuming a volute profile, calculate the volute tongue radius r, the shortest distance b2 at the volute throat, the volute outlet width b1, and multiple opening values ​​distributed along the circumference of the volute. The multiple opening values ​​include a1, a2, a3, a4, and a5, and the opening value is the distance between the impeller outlet and the inner wall of the volute.

[0009] Calculate the proportionality coefficients k1, k2, k3, k4 and k5;

[0010] Where, k1 = a1 / a2; k2 = a1 / a3, or k2 = a2 / a3; k3 = a3 / a4, or k3 = a1 / a4, or k3 = a2 / a4; k4 = a4 / a5, or k4 = a1 / a5, or k4 = a2 / a5, or k4 = a3 / a5; k5 = b1 / b2;

[0011] The target parameters of the centrifugal fan are to be determined as the values ​​of a1 and a2 corresponding to the optimal values.

[0012] Keeping the optimal value k1 unchanged, and keeping the assumed volute profile k3, k4, k5 and r unchanged, take multiple sets of k2 values, and solve for the target parameter a3 value corresponding to the optimal value;

[0013] Keeping the optimal values ​​k1 and k2 unchanged, and keeping the assumed volute profile k4, k5 and r unchanged, take multiple sets of k3 values, and solve for the target parameter a4 value corresponding to the optimal value;

[0014] Keeping the optimal values ​​k1, k2 and k3 unchanged, and keeping the assumed volute profile k5 and r unchanged, take multiple sets of k4 values, and find the target parameter a5 value corresponding to the optimal value.

[0015] Keeping the optimal values ​​k1, k2, k3 and k4 unchanged, and keeping the assumed volute profile r unchanged, take multiple sets of k5 values, and solve for the target parameter b1 value corresponding to the optimal value;

[0016] Keeping the optimal values ​​k1, k2, k3, k4 and b1 unchanged, and keeping the assumed volute profile r unchanged, take multiple sets of b2 values, and solve for the b2 value corresponding to the optimal value of the target parameter;

[0017] Keeping the optimal values ​​k1, k2, k3, k4, b2, and b1 unchanged, take multiple sets of r values ​​and solve for the r value corresponding to the optimal value of the target parameter.

[0018] Optionally, the step of determining the external dimensions of the volute includes:

[0019] Determine the dimension L of the volute along the first direction X, and determine the distance c, where c is the distance along the second direction Y between the position of the opening value a1 of the volute profile and the volute outlet;

[0020] The steps for determining the optimal values ​​of the target parameters a1 and a2 of the centrifugal fan include:

[0021] Calculate the proportionality coefficient k6 = c / a3, keep the assumed volute profile k2, k3, k4, k5, k6 and r unchanged, take multiple sets of k1 values, and solve for the a1 and a2 values ​​corresponding to the optimal values ​​of the target parameters of the centrifugal fan;

[0022] The step of finding the optimal value of the target parameter a3, and the step of finding the optimal value of the target parameter a4, further include the following:

[0023] Keeping the optimal values ​​k1 and k2 unchanged, and keeping the assumed volute profile k3, k4, k5 and r unchanged, take multiple sets of k6 values, and solve for the target parameter c value corresponding to the optimal value;

[0024] Wherein, a1 and a2 are the opening values ​​of the volute along the first direction X, a3 and a4 are the opening values ​​of the volute along the second direction Y, and a5 is the opening value near the volute tongue.

[0025] Optionally, the step of determining the external dimensions of the volute includes:

[0026] Determine the dimension W of the volute along the second direction Y, and determine the distance c, where c is the distance along the second direction Y between the position of the opening value a2 of the volute profile and the volute outlet;

[0027] The steps for determining the optimal values ​​of the target parameters a1 and a2 of the centrifugal fan include:

[0028] Calculate the proportionality constant k7 = c / a1;

[0029] Keeping the assumed volute profile k1, k2, k3, k4, k5 and r unchanged, take multiple sets of k7 values, and solve for the optimal values ​​of c and a1 corresponding to the target parameters of the centrifugal fan;

[0030] Keeping the optimal value k7 unchanged, and keeping the assumed volute profile k2, k3, k4, k5 and r unchanged, take multiple sets of k1 values, and solve for the target parameter a2 value of the centrifugal fan corresponding to the optimal value;

[0031] Wherein, a1 and a4 are the opening values ​​of the volute along the second direction Y, a2 and a3 are the opening values ​​of the volute along the first direction X, and a5 is the opening value near the volute tongue.

[0032] Optionally, the opening values ​​a1, a3, a2, a4 and a5 are located in a counterclockwise direction along the volute and their values ​​decrease sequentially.

[0033] Optionally, the opening values ​​a2, a1, a3, a4 and a5 are located in a counterclockwise direction along the volute and their values ​​decrease sequentially.

[0034] Optionally, the optimal value of the target parameter of the centrifugal fan is the maximum value of the air volume of the centrifugal fan, and / or, the optimal value of the target parameter of the centrifugal fan is the minimum value of the noise of the centrifugal fan.

[0035] Optionally, the air volume of the centrifugal fan is measured by numerical simulation or experiment.

[0036] Optionally, the noise of the centrifugal fan is measured by numerical simulation or experiment.

[0037] This application also provides a centrifugal fan, which is obtained by any of the above design methods.

[0038] The centrifugal fan volute profile design method provided in this application has the following advantages:

[0039] Under the constraints of the external structure, determine the external dimensions of the volute, including length L and / or width W, and determine the impeller outer diameter D, i.e., the relevant constrained dimensions of the given fan. Assuming a volute profile, calculate the values ​​of each structural parameter of this volute profile, and simultaneously calculate the proportional coefficient formed by two parameters. Using the controlled variable method, following a certain solution order, change one structural parameter at a time while keeping the other parameter values ​​unchanged, and solve for the parameter values ​​corresponding to the optimal values ​​of the target parameters, including airflow and / or noise. By sequentially determining the optimal solutions for each structural parameter under the constrained dimensions, the optimal solution for the volute profile is designed. This fan features high efficiency, strong suction, and low noise. Attached Figure Description

[0040] Figure 1 This is a flowchart of the centrifugal fan volute profile design method provided in the embodiments of this application;

[0041] Figure 2 This is a schematic diagram of the centrifugal fan structure according to an embodiment of this application;

[0042] Figure 3 This is a schematic diagram of the volute structure according to an embodiment of this application;

[0043] Figure 4 This is a schematic diagram of the impeller structure according to an embodiment of this application;

[0044] Figure 5 This is a schematic diagram of the installation position of the centrifugal fan in a household appliance according to an embodiment of this application;

[0045] Figure 6 This is a schematic diagram showing the distribution of volute structure parameters under a limited size L in an embodiment of this application;

[0046] Figure 7 This is a schematic diagram showing the distribution of the volute structure parameters under a limited size W in an embodiment of this application;

[0047] Figure 8 This is a schematic diagram of the air volume measurement test device according to an embodiment of this application.

[0048] Explanation of reference numerals in the attached figures:

[0049] 1-Centrifugal fan, 11-Volume casing, 111-Volume casing throat, 112-Volume casing body, 12-Impeller, 2-Inlet box, 31-Connector, 32-Cross rectifier, 33-Diffuser cavity, 34-Regulator, 35-Pressure reducing cylinder, 36-Static pressure tap, X-First direction, Y-Second direction. Detailed Implementation

[0050] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0051] like Figures 2 to 5 As shown, the centrifugal fan 1 includes a volute 11, an impeller 12, a collector, and a motor. The impeller 12 is located inside the volute 11. The distance between the outlet of the impeller 12 and the inner wall of the volute 11 is the opening. The volute 11 is a stationary working component. Along the clockwise direction, which is the airflow direction, the kinetic energy of the airflow in the volute 11 channel is gradually converted into static pressure energy, and the opening gradually increases. The diffusion degree of the airflow is inversely proportional to the ratio of the inlet cross-sectional area to the outlet cross-sectional area of ​​the airflow flow area. The upper end of the volute throat 111 is the volute outlet, and the volute tongue is the rounded corner between the volute throat 111 and the volute body 112.

[0052] Figure 1 A flowchart illustrating the centrifugal fan volute profile design method according to an embodiment of this application is shown. The method includes the following steps:

[0053] Step S1: Under limited conditions, determine the external dimensions of the volute 11 and the outer diameter D of the impeller 12;

[0054] Specifically, such as Figure 6 and Figure 7As shown, due to factors such as motor load and impeller rotational stability, the outer diameter of the impeller 12 is usually limited to a certain dimension D. The external dimensions of the volute 11 are related to the length and width dimensions of the air inlet box 2. In this embodiment, the dimension L of the volute along the first direction X and / or the dimension W of the volute along the second direction Y are limited.

[0055] Step S2: Assuming a volute profile, calculate the volute tongue radius r, the shortest distance b2 at the volute throat, the volute outlet width b1, and multiple opening values ​​distributed along the circumference of the volute. The multiple opening values ​​include a1, a2, a3, a4, and a5. The opening value is the distance between the impeller outlet and the inner wall of the volute.

[0056] Specifically, an unequal-sided primitive method is used to assume and draw a volute profile. The volute tongue radius *r*, the shortest distance *b2* at the volute throat, the volute outlet width *b1*, distance *c*, and multiple opening values ​​are obtained. The opening value represents the distance between the impeller 12 outlet and the inner wall of the volute 11 at different positions along the airflow direction. Three, four, five, or more opening values ​​can be used. The more opening values ​​obtained, the more accurate the determination of the volute profile, but the time cost of the method must be considered. This embodiment uses five opening values ​​as an example, distributed in different areas including the top, bottom, left, right, and volute tongue gap. Distance *c* is the vertical distance along the second direction Y between the position of the opening value closest to the volute outlet and the volute outlet in this embodiment. Figure 6 When the dimension L of the volute along the first direction X is limited, the distance c is the vertical distance between the position of the opening value a1 and the volute outlet. In this case, the distance c is related to the opening value a3; for example... Figure 7 When the dimension W of the volute along the second direction Y is limited, the distance c is the vertical distance between the position of the opening value a2 and the volute outlet. At this time, the distance c is related to the opening value a1.

[0057] like Figure 6As shown, when the dimension L of the volute along the first direction X is limited, the opening values ​​a1, a2, a3, a4, and a5 of the aforementioned volute profile, the radius r of the volute tongue, the distance c between the position of the opening value a1 and the volute outlet along the first direction X, the shortest distance b2 of the volute throat, and the volute outlet width b1 are obtained. Wherein, a1 and a2 are the opening values ​​of the volute along the first direction X, a3 and a4 are the opening values ​​of the volute along the second direction Y, and a5 is the opening value near the volute tongue. The positions of a1, a3, a2, a4, and a5 are distributed sequentially in a counterclockwise direction along the volute, and the values ​​of a1, a3, a2, a4, and a5 decrease sequentially. Since the opening value a1 is located near the volute outlet, and the surrounding flow area is the high-speed flow zone of the centrifugal fan, it has a significant impact on the fan performance. Therefore, the optimization design of the volute opening starts from the opening value a1 and rotates counterclockwise, so that the opening value of the volute profile increases continuously from the inlet to the outlet, ensuring that the volute profile does not become distorted. Furthermore, since the sum of a1, a2, and D is L, a1 and a2 are related parameters. And since the distance c is related to the opening value a3 and both are along the first direction X, the distance c can be calculated after solving for the opening value a3. Therefore, the parameter values ​​are determined in the following order: a1, a2, a3, c, a4, a5, b1, b2, and r.

[0058] like Figure 7 As shown, when the dimension W of the volute along the second direction Y is limited, the opening values ​​a1, a2, a3, a4, and a5 of the aforementioned volute profile, the radius r of the volute tongue, the distance c between the position of the opening value a2 and the volute outlet along the first direction X, the shortest distance b2 of the volute throat, and the volute outlet width b1 are obtained. Here, a1 and a4 are the opening values ​​of the volute along the second direction Y, a2 and a3 are the opening values ​​of the volute along the first direction X, and a5 is the opening value near the volute tongue. In this case, c and a1 are associated parameters; specifically, C + D / 2 + a1 = W, where W and D are predetermined values. The positions of a2, a1, a3, a4, and a5 are distributed sequentially along the counterclockwise direction of the volute, and the values ​​of a2, a1, a3, a4, and a5 decrease sequentially. At the same time, taking into account the principle that the opening value near the volute outlet should be determined first, the parameter values ​​are determined in the following order: c, a1, a2, a3, a4, a5, b1, b2 and r.

[0059] Step S3: Calculate the proportionality coefficients k1, k2, k3, k4 and k5;

[0060] Where, k1 = a1 / a2; k2 = a1 / a3, or k2 = a2 / a3; k3 = a3 / a4, or k3 = a1 / a4, or k3 = a2 / a4; k4 = a4 / a5, or k4 = a1 / a5, or k4 = a2 / a5, or k4 = a3 / a5; k5 = b1 / b2;

[0061] Specifically, after solving for a1 and a2, k2 is the ratio of any one of a1 and a2 to a3; after solving for a1, a2, and a3, k3 is the ratio of any one of a1, a2, and a3 to a4; and after solving for a1, a2, a3, and a4, k4 is the ratio of any one of a1, a2, a3, and a4 to a5.

[0062] For example, when defining the dimension L of the volute along the first direction X, the proportionality coefficients k1 = a1 / a2, k2 = a1 / a3, k3 = a3 / a4, k4 = a4 / a5, k5 = b1 / b2, k6 = c / a3 are calculated.

[0063] For example, when defining the dimension W of the volute along the second direction Y, the proportionality coefficients k1 = a1 / a2, k2 = a1 / a3, k3 = a3 / a4, k4 = a4 / a5, k5 = b1 / b2, and k7 = c / a1 are calculated.

[0064] Step S4: Solve for the optimal values ​​of the target parameters of the centrifugal fan, namely a1 and a2.

[0065] like Figure 6 When the dimension L of the volute along the first direction X is limited, keeping the assumed volute profile k2, k3, k4, k5, k6, and r constant, multiple sets of k1 values ​​are taken, and the optimal values ​​of a1 and a2 corresponding to the target parameters of the centrifugal fan are solved sequentially. The target parameters include airflow and / or noise. The target parameters are optimal when the airflow is maximum and / or the noise is minimum. In the following embodiments, the optimal solution for the target parameters is the case where the airflow is maximum. Specifically, multiple sets of a1 and a2 values ​​are taken. Since a1 and a2 are associated parameters, specifically, L = a1 + D + a2, where D is a fixed value, each a1 value corresponds to an a2 value, such as a11 and a21, a12 and a22, a13 and a23, and more. The corresponding airflow value is solved using numerical simulation or experimental methods. The optimal numerical solution is the a1 and a2 values ​​corresponding to the maximum airflow value.

[0066] like Figure 7 When the dimension W of the volute along the second direction Y is defined, step S4 includes the following steps:

[0067] Step S41: Keep the assumed volute profile k1, k2, k3, k4, k5 and r unchanged, take multiple sets of k7 values, and solve for the c and a1 values ​​corresponding to the maximum air volume of the centrifugal fan.

[0068] Specifically, since c and a1 are related parameters, each value of c corresponds to a value of a1. Numerical simulation or experimental methods are used to solve for the air volume value corresponding to each set of c and a1 values. The c and a1 values ​​corresponding to the maximum air volume value are the optimal numerical solutions.

[0069] Step S42: Keeping the assumed volute profile k2, k3, k4, k5 and r, and the optimal numerical solution k6 unchanged, take multiple sets of k1 values ​​and solve for the target parameter a2 value corresponding to the optimal value of the centrifugal fan.

[0070] Specifically, after determining the optimal solution a1 in step S41, the value of k1 is changed in step S41, which is equivalent to changing the value of a2. The value of a2 corresponding to the maximum air volume of the centrifugal fan is solved by numerical simulation or experimental methods.

[0071] Air volume is measured using numerical simulation methods or experiments, and noise can also be measured using numerical simulation methods or experiments. Air volume experimental measurement devices include... Figure 8 As shown, the device includes a connector 31, a cross rectifier 32, a diffuser 33, a regulator 34, and a pressure reducing cylinder 35 connected in sequence, with a static pressure tap 36 on the pressure reducing cylinder 35. Before testing, the fan must be run stably for one hour at its rated voltage, rated frequency, and highest normal operating speed. During the test, the fan outlet is connected to the test device. By changing the orifice plate of different diameters after replacing the pressure reducing cylinder 35, the fan outlet resistance is changed, thereby measuring the static pressure inside the pressure reducing cylinder 35 and the main motor input power at various operating points. Finally, the aerodynamic performance curves of the experimental equipment, including static pressure, total pressure, flow rate, and efficiency, are calculated. The noise test of the centrifugal fan is conducted in a semi-anechoic chamber, and the noise measurement method is the global envelope method.

[0072] Step S5: Keep the optimal value k1 unchanged, and keep the assumed volute profile k3, k4, k5 and r unchanged, take multiple sets of k2 values, and solve for the target parameter a3 value corresponding to the optimal value.

[0073] Specifically, such as Figure 6 When the dimension L of the volute along the first direction X is limited, the optimal value k1 is kept unchanged, and the assumed volute profiles k3, k4, k5, k6 and r are kept unchanged. Since the optimal solution of a1 has been determined, multiple sets of k2 values ​​are taken, that is, multiple a3 values ​​are taken. The a3 value corresponding to the maximum air volume of the centrifugal fan is solved by numerical simulation method or experimental method.

[0074] Furthermore, when defining the dimension L of the volute along the first direction X, the following steps are also included between steps S5 and S6:

[0075] Since c and a3 are associated parameters under the condition of the size L of the volute along the first direction X, the optimal values ​​k1 and k2 are kept unchanged, and the assumed volute profile k3, k4, k5 and r are kept unchanged. The optimal opening value a3 determined in the previous step is kept unchanged. Multiple sets of k6 values ​​are taken to solve the distance c value corresponding to the maximum air volume of the centrifugal fan.

[0076] Specifically, such as Figure 7 When the dimension W of the volute along the second direction Y is limited, the optimal values ​​k1 and k7 are kept unchanged, and the assumed volute profiles k3, k4, k5 and r are kept unchanged. Since the optimal solution of a1 has been determined, multiple sets of k2 values ​​are taken, that is, multiple a3 values ​​are taken. The a3 value corresponding to the maximum air volume of the centrifugal fan is solved by numerical simulation method or experimental method.

[0077] Step S6: Keep the optimal values ​​k1 and k2 unchanged, and keep the assumed volute profile k4, k5 and r unchanged. Take multiple sets of k3 values ​​and solve for the target parameter a4 value corresponding to the optimal value.

[0078] Specifically, such as Figure 6 When the dimension L of the volute along the first direction X is limited, the optimal values ​​k1, k2 and k6 are kept unchanged, and the assumed volute profile k4, k5 and r are kept unchanged. Since the optimal solution of a3 has been determined, multiple sets of k3 values ​​are taken, that is, multiple a4 values ​​are taken. The a4 value corresponding to the maximum air volume of the centrifugal fan is solved by numerical simulation method or experimental method.

[0079] Specifically, such as Figure 7 When the dimension W of the volute along the second direction Y is limited, the optimal values ​​k1, k2 and k7 are kept unchanged, and the assumed volute profile k4, k5 and r are kept unchanged. Since the optimal solution of a3 has been determined, multiple sets of k3 values ​​are taken, that is, multiple a4 values ​​are taken. The a4 value corresponding to the maximum air volume of the centrifugal fan is solved by numerical simulation method or experimental method.

[0080] Step S7: Keep the optimal values ​​k1, k2 and k3 unchanged, and keep the assumed volute profile k5 and r unchanged. Take multiple sets of k4 values ​​and find the target parameter a5 value corresponding to the optimal value.

[0081] Specifically, such as Figure 6 When the dimension L of the volute along the first direction X is limited, the optimal values ​​k1, k2, k3 and k6 are kept unchanged, and the k5 and r of the volute profile are kept unchanged. Since the optimal solution of a4 has been determined, multiple sets of k4 values ​​are taken, which means multiple a5 values ​​are taken. The a5 value corresponding to the maximum air volume of the centrifugal fan is solved by numerical simulation method or experimental method.

[0082] Specifically, such as Figure 7When the dimension W of the volute along the second direction Y is limited, the optimal values ​​k1, k2, k3 and k7 are kept unchanged, and the k5 and r of the volute profile are kept unchanged. Since the optimal solution of a4 has been determined, multiple sets of k4 values ​​are taken, which means multiple a5 values ​​are taken. The a5 value corresponding to the maximum air volume of the centrifugal fan is solved by numerical simulation method or experimental method.

[0083] Step S8: Keep the optimal values ​​k1, k2, k3 and k4 unchanged, and keep the assumed volute profile r unchanged. Take multiple sets of k5 values ​​and solve for the target parameter b1 value corresponding to the optimal value.

[0084] Specifically, such as Figure 6 When the dimension L of the volute along the first direction X is limited, the optimal values ​​k1, k2, k3, k4 and k6 are kept unchanged, and the assumed volute profile r is kept unchanged. Multiple sets of k5 values ​​are taken, and the b1 value corresponding to the maximum air volume of the centrifugal fan is solved by numerical simulation method or experimental method.

[0085] Specifically, such as Figure 7 When the dimension W of the volute along the second direction Y is limited, the optimal values ​​k1, k2, k3, k4 and k7 are kept unchanged, and the assumed volute profile r is kept unchanged. Multiple sets of k5 values ​​are taken, and the b1 value corresponding to the maximum air volume of the centrifugal fan is solved by numerical simulation method or experimental method.

[0086] Step S9: Keep the optimal values ​​k1, k2, k3, k4 and b1 unchanged, and keep the assumed volute profile r unchanged. Take multiple sets of b2 values ​​and solve for the b2 value corresponding to the optimal value of the target parameter.

[0087] Specifically, such as Figure 6 When the dimension L of the volute along the first direction X is limited, the optimal values ​​k1, k2, k3, k4, k6 and b1 are kept unchanged, and the assumed volute profile r is kept unchanged. Multiple sets of b2 values ​​are taken, and the b2 value corresponding to the maximum air volume of the centrifugal fan is solved by numerical simulation method or experimental method.

[0088] Specifically, such as Figure 7 When the dimension W of the volute along the second direction Y is limited, the optimal values ​​k1, k2, k3, k4, k7 and b1 are kept unchanged, and the assumed volute profile r is kept unchanged. Multiple sets of b2 values ​​are taken, and the b2 value corresponding to the maximum centrifugal fan air volume is solved by numerical simulation method or experimental method.

[0089] Step S10: Keep the optimal values ​​k1, k2, k3, k4, b2 and b1 unchanged, take multiple sets of r values, and solve for the r value corresponding to the optimal value of the target parameter.

[0090] Specifically, such as Figure 6 When the dimension L of the volute along the first direction X is limited, the optimal values ​​k1, k2, k3, k4, k6, b2 and b1 are kept unchanged. Multiple sets of r values ​​are taken, and the r value corresponding to the maximum air volume of the centrifugal fan is solved by numerical simulation method or experimental method.

[0091] Specifically, such as Figure 7 When the dimension W of the volute along the second direction Y is limited, the optimal values ​​k1, k2, k3, k4, k7, b2 and b1 are kept unchanged. Multiple sets of r values ​​are taken, and the r value corresponding to the maximum air volume of the centrifugal fan is solved by numerical simulation method or experimental method.

[0092] Therefore, using the above design method, the optimal numerical solutions for a1, a2, a3, a4, a5, b2, b1, c, and r of the volute profile were determined sequentially. Under the constraints of the volute's external dimensions and the impeller's outer diameter, the controlled variable method was employed. Following a specific solution sequence, one structural parameter was changed each time, and the optimal values ​​for the target parameters, including airflow and / or noise, were determined. By sequentially determining the optimal solutions for each structural parameter, the optimal solution for the volute profile was designed. This solution maximizes the fan's airflow or minimizes noise, achieving optimal aerodynamic performance while maintaining high fan efficiency.

[0093] This embodiment also provides a centrifugal fan, see reference. Figure 2 This centrifugal fan, obtained using any of the above design methods, maximizes airflow and minimizes noise and vibration within a limited size, achieving optimal aerodynamic performance and high fan efficiency.

[0094] The centrifugal fan provided in this embodiment can be installed inside the air intake box of an air conditioner. The centrifugal fan provides the air conditioner with strong and stable airflow, resulting in better indoor air circulation and maintaining air cleanliness. The air conditioner can achieve maximum airflow and minimum noise and vibration within a limited size range.

[0095] In addition, such as Figure 5 As shown, the centrifugal fan 1 in this embodiment can also be installed in the air inlet box 2 of the range hood to ensure that oil fumes and other exhaust gases are effectively discharged.

[0096] It should be noted that, for the sake of simplicity, the method embodiments are all described as a series of actions. However, those skilled in the art should understand that the embodiments of this application are not limited to the described order of actions, because according to the embodiments of this application, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also understand that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily essential to the embodiments of this application.

[0097] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0098] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A method for designing a volute profile of a centrifugal fan, the centrifugal fan comprising a volute and an impeller disposed inside the volute, characterized in that: The method comprises: Under limited conditions, determine the external dimensions of the volute and the outer diameter D of the impeller, wherein the limited conditions refer to the outer diameter of the impeller and the size of the air inlet box; Assuming a volute profile, obtain the volute tongue radius r, the shortest distance b2 of the volute throat, the volute outlet width b1, and a plurality of opening values ​​distributed along the circumference of the volute, wherein the plurality of opening values ​​include a1, a2, a3, a4, and a5, and the opening value is the distance between the impeller outlet and the inner wall of the volute; Calculate the proportionality coefficients k1, k2, k3, k4 and k5; Among them, k1=a1 / a2; k2=a1 / a3, or, k2=a2 / a3; k3=a3 / a4, or, k3=a1 / a4, or, k3=a2 / a4; k4=a4 / a5, or, k4=a1 / a5, or, k4=a2 / a5, or, k4=a3 / a5; k5=b1 / b2; Solving the target parameter of the centrifugal fan for the values ​​of a1 and a2 corresponding to the optimal values, the optimal value of the target parameter of the centrifugal fan being the maximum value of the air volume of the centrifugal fan, and / or the optimal value of the target parameter of the centrifugal fan being the minimum value of the noise of the centrifugal fan; Keep the optimal value k1 unchanged, and keep the assumed volute profile k3, k4, k5 and r unchanged, take multiple sets of k2 values, and solve the a3 value corresponding to the optimal value of the target parameter; Keep the optimal values ​​k1 and k2 unchanged, and keep the assumed volute profile k4, k5 and r unchanged, take multiple sets of k3 values, and solve the a4 value corresponding to the optimal value of the target parameter; Keep the optimal values ​​k1, k2 and k3 unchanged, and keep the k5 and r of the assumed volute profile unchanged, take multiple sets of k4 values, and find the a5 value corresponding to the optimal value of the target parameter; Keep the optimal values ​​k1, k2, k3 and k4 unchanged, and keep the assumed volute profile r unchanged, take multiple sets of k5 values, and solve the b1 value corresponding to the optimal value of the target parameter; Keep the optimal values ​​k1, k2, k3, k4 and b1 unchanged, and keep the assumed volute profile r unchanged, take multiple groups of b2 values, and solve the b2 value corresponding to the optimal value of the target parameter; Keeping the optimal values ​​k1, k2, k3, k4, b2 and b1 unchanged, taking multiple groups of r values, and solving the r value corresponding to the optimal value of the target parameter.

2. The design method according to claim 1, characterized in that: The step of determining the outer dimensions of the volute comprises: Determine the dimension L of the volute along the first direction X, and determine the distance c, where c is the distance between the position where the opening value a1 of the volute profile is located and the volute outlet along the second direction Y; The step of solving the target parameter of the centrifugal fan for the a1 and a2 values ​​corresponding to the optimal values ​​comprises: Calculate the proportionality coefficient k6=c / a3, keep k2, k3, k4, k5, k6 and r of the assumed volute profile unchanged, take multiple sets of k1 values, and solve the a1 and a2 values ​​corresponding to the optimal values ​​of the target parameters of the centrifugal fan; The step of solving the a3 value corresponding to the optimal value of the target parameter and the step of solving the a4 value corresponding to the optimal value of the target parameter further include: Keep the optimal values ​​k1 and k2 unchanged, and keep the assumed volute profile k3, k4, k5 and r unchanged, take multiple sets of k6 values, and solve the c value corresponding to the optimal value of the target parameter; Among them, a1 and a2 are the opening values ​​of the volute along the first direction X, a3 and a4 are the opening values ​​of the volute along the second direction Y, and a5 is the opening value near the volute tongue.

3. The design method according to claim 1, characterized in that: The step of determining the outer dimensions of the volute comprises: Determine the dimension W of the volute along the second direction Y, and determine the distance c, where c is the distance between the position where the opening value a2 of the volute profile is located and the volute outlet along the second direction Y; The step of solving the target parameter of the centrifugal fan for the a1 and a2 values ​​corresponding to the optimal values ​​comprises: Calculate the proportionality coefficient k7 = c / a1; Keeping k1, k2, k3, k4, k5 and r of the assumed volute profile unchanged, taking multiple sets of k7 values, and solving the c and a1 values ​​corresponding to the optimal values ​​of the target parameters of the centrifugal fan; Keep the optimal value k7 unchanged, and keep k2, k3, k4, k5 and r of the assumed volute profile unchanged, take multiple sets of k1 values, and solve the a2 value corresponding to the optimal value of the target parameter of the centrifugal fan; Among them, a1 and a4 are the opening values ​​of the volute along the second direction Y, a2 and a3 are the opening values ​​of the volute along the first direction X, and a5 is the opening value near the volute tongue.

4. The design method according to claim 2, characterized in that: The positions of the opening values ​​a1, a3, a2, a4 and a5 are distributed in sequence along the counterclockwise direction of the volute and the values ​​decrease in sequence.

5. The design method according to claim 3, characterized in that: The positions of the opening values ​​a2, a1, a3, a4 and a5 are distributed in sequence along the counterclockwise direction of the volute and the values ​​decrease in sequence.

6. The design method according to claim 1, characterized in that: The air volume of the centrifugal fan is measured by numerical simulation method or experiment.

7. The design method according to claim 1, characterized in that: The noise of the centrifugal fan is measured by numerical simulation method or experiment.

8. A centrifugal fan, characterized in that: The centrifugal fan is obtained by adopting the design method described in any one of claims 1 to 7.

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