A blade design method, a blade design system, a blade and a high-efficiency constant-thickness impeller

Abstract

The application discloses a blade design method, a blade design system, a blade and a high-efficiency equal-thickness impeller. The blade design method comprises the following steps: obtaining target design parameters, including an impeller diameter and a number of blades; determining a blade chord length according to the impeller diameter; determining a blade camber corresponding to the blade chord length by using a fitting optimization curve of the chord length and the camber according to the blade chord length; determining a blade height according to the impeller diameter and the number of blades; and obtaining a blade element according to the blade camber, stretching the height of a corresponding position of the blade element to the blade height, and obtaining a target blade structure. Since the blade camber is obtained by using the fitting optimization curve, the blade camber has the same characteristics as the fitting optimization curve, and repeated checking and adjustment are not needed in the design process, the design method is simple, and batch and rapid design can be realized.

Description

Technical Field

[0001] This invention relates to the field of wind turbine design technology, and more specifically, to a blade design method. Furthermore, this invention also relates to a blade design system, a blade, and a high-efficiency, uniform-thickness impeller. Background Technology

[0002] As one of the key pieces of equipment in energy systems, wind turbines are constantly being updated and upgraded. The pursuit of high efficiency in wind turbines has become an inevitable trend of the times. Therefore, the design of wind turbine impellers has become the most critical step in wind turbine design.

[0003] There are various design tools and methods for wind turbines, but designing an efficient wind turbine requires not only strong theoretical support but also extensive verification using test data to ultimately achieve a design that meets the operating conditions. However, the design process is quite complicated, resulting in low design efficiency.

[0004] In conclusion, how to solve the problem of low efficiency in wind turbine design is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a blade design method that can improve design efficiency.

[0006] Another object of the present invention is to provide a blade design system, blades, and high-efficiency equal-thickness impeller that includes the blade design method described above.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A blade design method, comprising:

[0009] Obtain the target design parameters, including impeller diameter and number of blades;

[0010] The blade chord length is determined based on the impeller diameter;

[0011] Based on the blade chord length, the blade camber corresponding to the blade chord length is determined using the fitting optimization curve of chord length and camber.

[0012] The blade height is determined based on the impeller diameter and the number of blades;

[0013] Based on the blade camber, obtain the blade element, and stretch the height of the corresponding position of the blade element to the blade height to obtain the target blade structure.

[0014] Preferably, determining the blade chord length based on the impeller diameter includes:

[0015] The blade chord length is determined using the formula L = (0.4 ~ 0.6)D;

[0016] Where L is the blade chord length and D is the impeller diameter.

[0017] Preferably, based on the blade chord length, the blade camber corresponding to the blade chord length is determined using a fitting optimization curve of the chord length and camber:

[0018] Divide the blade chord length n into equal parts, and take the reference position x as values ​​of 0, 1 / n, ..., n / n in sequence, using the formula:

[0019] y = 2.797x 6 -6.9249x 5 +5.8101x 4 -1.8368x 3 -0.4797x 2 +0.6343x;

[0020] h = Ly;

[0021] Obtain the camber h of the n+1 reference positions x corresponding to the n+1 reference positions x respectively;

[0022] Where y is the ratio of the camber of the reference position to the chord length of the blade, x is the ratio of the chord length of the reference position to the chord length of the blade, h is the camber of the reference position, and L is the chord length of the blade.

[0023] Preferably, n is greater than or equal to 4.

[0024] Preferably, the blade height is determined based on the impeller diameter and the number of blades, including determining the blade height using the following formula:

[0025] H = (0.5~2)D / z;

[0026] Wherein, H is the blade height, D is the impeller diameter, and z is the number of blades.

[0027] Preferably, after obtaining the blade element based on the blade camber, stretching the height of the corresponding position of the blade element to the blade height to obtain the target blade structure, the method further includes:

[0028] Obtain the models of the roulette wheel and its cover;

[0029] The final target impeller structure is determined by performing a Boolean summation operation on the target blade structure, the impeller disk model, and the impeller cover model.

[0030] A blade design system, comprising:

[0031] The data acquisition module is used to acquire target design parameters, including impeller diameter and number of blades;

[0032] The design module is used to determine the blade chord length based on the impeller diameter; to determine the blade camber corresponding to the blade chord length using a fitting optimization curve of chord length and camber; and to determine the blade height based on the impeller diameter and the number of blades.

[0033] The forming module is used to obtain blade elements based on the blade camber, and stretch the height of the corresponding position of the blade elements to the blade height to obtain the target blade structure.

[0034] The data acquisition module is connected to the design module, and the design module is connected to the molding module.

[0035] Preferred options also include:

[0036] A model acquisition module, which is used to acquire the model of the wheel and the model of the wheel cover;

[0037] The calculation module is used to perform Boolean summation on the target blade structure, the model of the impeller, and the model of the wheel cover to determine the final target impeller structure; the calculation module is connected to the model acquisition module and the forming module.

[0038] A blade, wherein the blade is manufactured by the blade design method described above.

[0039] A high-efficiency constant-thickness impeller includes blades, wherein the blades are those described above.

[0040] The blade design method provided by this invention obtains the blade chord length, blade camber, and blade height from the acquired impeller diameter and number of blades. The blade camber is calculated using an existing fitted optimization curve. Since the selected fitted optimization curve is characterized by high efficiency and low loss, the blade camber obtained using the current blade chord length and the fitted optimization curve also possesses the characteristics of this curve, namely, high efficiency and low loss. The blade camber is used to obtain blade elements, and the blade elements are stretched to obtain the airfoil, which also features high efficiency and low loss. In this process, repeated verification and adjustment are unnecessary; only the conditions of the fitted optimization curve need to be met. Therefore, this design process is highly efficient, simple, and enables batch and rapid design.

[0041] The present invention also provides a blade design system, a blade, and a high-efficiency equal-thickness impeller. Since they all use the above-mentioned blade design method, they all have the same effect as the blade design method. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0043] Figure 1 A flowchart of the blade design method provided by the present invention;

[0044] Figure 2 This is a schematic diagram of the target impeller structure provided by the present invention;

[0045] Figure 3 This is a schematic diagram of the blade element provided by the present invention;

[0046] Figure 4 This is a schematic diagram of the target blade structure provided by the present invention;

[0047] Figure 5 This is a schematic diagram of the fitting optimization curve provided by the present invention;

[0048] Figure 6 This is a graph showing the relationship between flow rate and pressure when the blades are in use, obtained by the method provided in this invention.

[0049] Figure 7 This is a graph showing the relationship between flow rate and efficiency when the blades obtained by the method provided in this invention are in use.

[0050] Figure 1-5 middle:

[0051] 1 is the model of the wheel cover, 2 is the model of the wheel disk, 3 is the target blade structure, h is the blade camber, L is the blade chord length, and H is the blade height. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] The core of this invention is to provide a blade design method that can improve design efficiency. Another core aspect of this invention is to provide a blade design system, blades, and a high-efficiency equal-thickness impeller that incorporates the aforementioned blade design method.

[0054] Please refer to Figures 1-5 , Figure 1 A flowchart of the blade design methodology; Figure 2 Here is a schematic diagram of the target impeller structure; Figure 3 A schematic diagram of a blade element; Figure 4 This is a schematic diagram of the target blade structure; Figure 5 A schematic diagram for fitting and optimizing the curve.

[0055] This application provides a blade design method, which specifically includes the following steps:

[0056] Step S1: Obtain the target design parameters, including impeller diameter and number of blades;

[0057] Step S2: Determine the blade chord length L based on the impeller diameter D;

[0058] Based on the blade chord length L, the blade camber h corresponding to the blade chord length L is determined by using the fitting optimization curve of chord length and camber.

[0059] The blade height H is determined based on the impeller diameter D and the number of blades z.

[0060] Step S3: Obtain the blade element based on the blade camber h, and stretch the height of the corresponding position of the blade element to the blade height H to obtain the target blade structure 3.

[0061] The impeller diameter D and the number of blades z are determined based on operating conditions and customer requirements. The impeller diameter D is typically determined by considering three factors:

[0062] First, the size of the impeller is limited by the size of the customer's installation dimensions, such as the size of the end products like air conditioners, air purifiers, range hoods, and vacuum cleaners.

[0063] Secondly, it depends on the operating conditions, mainly including parameters such as impeller air volume, pressure, power and efficiency. For example, if the impeller diameter D is too small, the pressure and flow rate will not reach the design target value, and can only be achieved by increasing the size; if the impeller diameter D is too large, the working range of the impeller is too large, and the pressure and flow rate efficiency is relatively low, so it is necessary to reduce the size or use other methods to improve efficiency.

[0064] Third, based on existing products, considering market versatility and manufacturers that are currently performing well, the dimensions of existing products can be used as a reference.

[0065] The final impeller diameter is determined by considering all the above factors. In this application, the impeller diameter D can be obtained directly from the designer, for example, by inputting it through an input device, or by transmitting it from another device.

[0066] The number of blades z is usually determined by two aspects:

[0067] On the one hand, the number of blades in centrifugal fans is currently mainly 4-9.

[0068] On the other hand, it is also based on the operating conditions, mainly including parameters such as air volume, pressure, power and efficiency, and through simulation or experimentation, the optimal number of blades z is tested and determined.

[0069] In addition, the above-mentioned fitting optimization curve can be the result of a large number of simulations and experiments. First, the optimal blade element scheme is obtained through simulation and experiment. Then, based on the different positions of the obtained blade element chord length and the corresponding camber, the fitting optimization curve of chord length and camber is finally obtained.

[0070] Since the blade camber h in the blade design method provided by this invention is obtained through an existing fitting optimization curve, and the fitting optimization curve can be a curve with high efficiency and low loss, the final target blade structure 3 also has the characteristics of high efficiency and low loss. More importantly, in the design process, by using the method of obtaining the target blade structure 3 by using the existing fitting optimization curve, it is only necessary to substitute the blade chord length L into the curve to obtain the target blade structure 3 corresponding to the current blade chord length L. There is no need for repeated verification and adjustment. It is only necessary to meet the conditions of the fitting optimization curve. Therefore, the design method is simple and can realize batch and fast design.

[0071] Optionally, the fitted optimization curve can also be a curve with other characteristics.

[0072] Based on the above embodiments, step S2, which involves determining the blade chord length L according to the impeller diameter D, specifically includes the following steps:

[0073] Step S21: Determine the blade chord length L according to the formula L = (0.4 ~ 0.6)D;

[0074] Where L is the blade chord length and D is the impeller diameter.

[0075] The impeller diameter D determines the maximum and minimum dimensions of the blade chord length L. If the blade chord length L is too large, there is a risk of exceeding the impeller diameter D and interference between blades. If the blade chord length L is too small, there is a problem of unreasonable impeller arrangement.

[0076] The above parameters can be obtained through simulation testing using fluid simulation software, and the optimal blade chord length L obtained from these parameters can be determined. Based on the formula for determining the blade chord length L derived from numerous simulation tests, it can be guaranteed that the final target blade structure under condition 3 has the optimal parameters, thereby improving the blade's working efficiency.

[0077] Based on the above embodiments, step S2, which involves determining the blade camber h corresponding to the blade chord length L using a fitting optimization curve of chord length and camber, specifically includes the following steps:

[0078] Step S22: Divide the blade chord length L into n equal parts. When the reference position x takes values ​​of 0, 1 / n, ..., n / n, use the formula:

[0079] y = 2.797x 6 -6.9249x 5 +5.8101x 4 -1.8368x 3 -0.4797x 2 +0.6343x;

[0080] h = Ly;

[0081] Obtain the camber h of the n+1 reference positions corresponding to the n+1 reference positions x respectively;

[0082] Where y is the ratio of the camber at the reference position to the blade chord length L, x is the ratio of the chord length at the reference position to the blade chord length L, h is the camber at the reference position, and L is the blade chord length.

[0083] Among them, through extensive testing, the initial fitted optimization curve equation obtained based on the optimal blade element is as follows:

[0084] y = 2.797x 6 -6.9249x 5 +5.8101x 4 -1.8368x 3 -0.4797x 2 +0.6343x+7E-06

[0085] Since the curve needs to pass through the point (0,0) in order to achieve the desired shape of the blade element, the constant 7E-06 in the above formula is discarded. This does not affect the shape of the curve, and the final fitted optimization curve equation has little effect on the blade chord length L.

[0086] The fitting optimization curve is characterized by high efficiency and low loss, and is applicable to the design of blades of different sizes. Therefore, during the design process, the blade camber h can be obtained by fitting the optimization curve equation without repeated verification and adjustment. The design method is simple and can realize batch and fast design. The designed blades also have the characteristics of high efficiency and low loss.

[0087] Based on the above embodiments, n is greater than or equal to 4.

[0088] If n is less than 4, the number of segments into which the blade chord length L is divided is too small, and the interval between each reference position is too large. Even after obtaining the camber at each reference position, the deviation from the fitted optimization curve is large. Therefore, the drawn blade element may not have the characteristics of high efficiency and low loss, and the error is large.

[0089] In this embodiment, please refer to Figure 5 If n is chosen to be 9, then x takes values ​​of 0, 1 / 9, 2 / 9...9 / 9 in sequence. Based on the chord length corresponding to the chosen x, the camber corresponding to the chord length can be obtained. Finally, the chord length and camber are used to fit the optimized curve shown in the figure.

[0090] Based on the above embodiments, step S2, which involves determining the blade height H based on the impeller diameter D and the number of blades z, specifically includes the following steps:

[0091] Step S23: Determine the blade height using the following formula: H = (0.5~2)D / z;

[0092] Where H is the blade height, D is the impeller diameter, and z is the number of blades.

[0093] If the blade height H is too high or too low, it will not meet the installation dimensions. After testing, it was found that the blade performance is optimal when the blade height H is within the range specified by the above formula, which can reduce losses.

[0094] Based on any of the above schemes, after obtaining the blade element according to the blade camber h in step S3, and stretching the height of the corresponding position of the blade element to the blade height H to obtain the target blade structure 3, the following steps are also included:

[0095] Step S4: Obtain the 2nd model of the roulette wheel and the 1st model of the wheel cover;

[0096] Step S5: Perform a Boolean summation operation on the target blade structure 3, the impeller model 2, and the wheel cover model 1 to determine the final target impeller structure.

[0097] Specifically, the intersection of the target blade structure 3, the disk model 2, and the wheel cover model 1 according to the preset positional relationship is obtained through Boolean summation operation. The redundant parts are removed, and the target impeller structure is finally obtained.

[0098] By using Boolean summation, the design process becomes simpler, and the final target impeller structure achieves higher efficiency and greater pressure.

[0099] Please refer to Figure 6 and Figure 7 , Figure 6 This is a graph showing the relationship between flow rate and pressure when the blades are in use, obtained by the method provided in this invention. Figure 7 This is a graph showing the relationship between flow rate and efficiency when the blades obtained by the method provided in this invention are in use. The blades obtained using the design method provided in this application exhibit characteristics similar to the original curve during use. For example, compared to blades obtained by ordinary design methods, the blades obtained in this application can withstand greater pressure and achieve higher efficiency under the same flow rate conditions.

[0100] In addition to the blade design method described above, the present invention also provides a blade design system for implementing the above method. The blade design system mainly includes, in terms of structure, a data acquisition module, a design module, and a forming module.

[0101] The data acquisition module is used to acquire target design parameters, including impeller diameter D and number of blades z.

[0102] The design module is used to determine the blade chord length L based on the impeller diameter D; to determine the blade camber h corresponding to the blade chord length L using the fitting optimization curve of chord length and camber; and to determine the blade height H based on the impeller diameter D and the number of blades z.

[0103] The forming module is used to obtain the blade basic element according to the blade camber h, and stretch the height of the corresponding position of the blade basic element to the blade height H to obtain the target blade structure 3.

[0104] The data acquisition module is connected to the design module, and the design module is connected to the molding module.

[0105] In use, after the data acquisition module obtains the target design parameters, it transmits the parameters to the design module. The design module obtains the blade chord length L, blade camber h, and blade height H based on the parameters. The design module then transmits the obtained data to the forming module, which stretches out the target blade structure 3 based on the obtained data.

[0106] The design module includes three sub-modules: chord length design module, camber design module, and height design module.

[0107] The chord length design module is used to determine the blade chord length L based on the impeller diameter D. Specifically, the blade chord length is determined using the formula L = (0.4 ~ 0.6)D.

[0108] Where L is the blade chord length and D is the impeller diameter.

[0109] The camber design module is used to determine the blade camber h corresponding to the blade chord length L using a fitting optimization curve of chord length and camber. Specifically, the blade chord length n is divided into equal parts, and the reference position x takes values ​​of 0, 1 / n, ..., n / n in sequence, according to the formula:

[0110] y = 2.797x 6 -6.9249x 5 +5.8101x 4 -1.8368x 3 -0.4797x 2 +0.6343x;

[0111] h = Ly;

[0112] Obtain the camber h corresponding to each of the n+1 reference positions x;

[0113] Where y is the ratio of the camber at the reference position to the blade chord length, x is the ratio of the chord length at the reference position to the blade chord length, h is the camber at the reference position, and L is the blade chord length.

[0114] And n is greater than or equal to 4.

[0115] The height design module is used to determine the blade height H based on the impeller diameter D and the number of blades z. Specifically, the blade height is determined using the following formula:

[0116] H = (0.5~2)D / z;

[0117] Where H is the blade height, D is the impeller diameter, and z is the number of blades.

[0118] The data acquisition module, the forming module, and the above three sub-modules are each equipped with an input unit and an output unit. The input unit of the data acquisition module is connected to the input device, the output unit is connected to the input unit of the chord length design module, the output unit of the chord length design module is connected to the input unit of the camber design module, the output unit of the camber design module is connected to the input unit of the height design module, and the output unit of the height design module is connected to the input unit of the forming module.

[0119] Based on the above embodiments, it also includes a model acquisition module and a calculation module. The model acquisition module is used to acquire the model 2 of the wheel disk and the model 1 of the wheel cover. The calculation module is used to perform Boolean summation on the target blade structure 3, the model 2 of the wheel disk and the model 1 of the wheel cover to determine the final target impeller structure. The model acquisition module is connected to the calculation module, and the calculation module is connected to the molding module.

[0120] After the forming module obtains the target blade structure 3, it transmits the target blade structure 3 to the calculation module. The model acquisition module transmits the acquired disk model 2 and wheel cover model 1 to the calculation module. The calculation module performs Boolean summation on the target blade structure 3, disk model 2 and wheel cover model 1 to finally obtain the target impeller structure.

[0121] The blade design system described above is used to execute the blade design method. The functions of each part can be specifically referred to the steps of the above method. This embodiment is a brief description. Those skilled in the art can refer to the above method to obtain the various functional operations of the system.

[0122] In addition to the blade design method and blade design system described above, the present invention also provides a blade, which is a blade manufactured according to the blade design method of the above embodiments, and a high-efficiency equal-thickness impeller, including a blade, which is a blade manufactured according to the blade design method of the above embodiments. The structure of the blade and other parts of the high-efficiency equal-thickness impeller can be referred to the prior art, and will not be described in detail here.

[0123] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0124] The blade design method and system, blades, and high-efficiency equal-thickness impellers provided by this invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. A blade design method, characterized by, The method comprises the following steps: obtaining target design parameters, including impeller diameter and blade number; determining blade chord length according to the impeller diameter; determining blade camber corresponding to the blade chord length by using a fitting optimization curve of chord length and camber according to the blade chord length; determining blade height according to the impeller diameter and the blade number; obtaining a blade primitive according to the blade camber, and stretching the height of a corresponding position of the blade primitive to the blade height to obtain a target blade structure (3).

2. The blade design method of claim 1, wherein The step of determining blade chord length according to the impeller diameter comprises the following steps: determining the blade chord length according to the formula L = (0.4-0.6)D; wherein L is the blade chord length, and D is the impeller diameter.

3. The blade design method of claim 1, wherein The step of determining blade camber corresponding to the blade chord length by using a fitting optimization curve of chord length and camber according to the blade chord length comprises the following steps: dividing the blade chord length n into equal parts, and taking the reference position x as 0, 1 / n, …, n / n in turn, and obtaining the camber h of the n+1 reference positions x corresponding to the n+1 reference positions x by using the formula h = Ly; y = 2.797x 6 -6.9249x 5 +5.8101x 4 -1.8368x 3 -0.4797x 2 +0.6343x; wherein y is the proportion of the camber of the reference position to the blade chord length, x is the proportion of the chord length of the reference position to the blade chord length, h is the camber of the reference position, and L is the blade chord length. The n is greater than or equal to 4. The step of determining blade height according to the impeller diameter and the blade number comprises the following steps:

4. The blade design method of claim 3, wherein determining the blade height by using the formula H = (0.5-2)D / z; 5. The blade design method of claim 1, wherein wherein H is the blade height, D is the impeller diameter, and z is the blade number. The method further comprises the following steps after the step of obtaining a blade primitive according to the blade camber, and stretching the height of a corresponding position of the blade primitive to the blade height to obtain a target blade structure (3): obtaining a model (2) of a wheel disc and a model (1) of a wheel cover; 6. A blade design method according to any one of claims 1 to 5, characterised in that, performing Boolean sum operation on the target blade structure (3), the model (2) of the wheel disc and the model (1) of the wheel cover to determine a final target impeller structure. The method comprises the following steps: a data acquisition module is configured to obtain target design parameters, including impeller diameter and blade number; 7. A blade design system, characterized by a design module is configured to determine blade chord length according to the impeller diameter; a module is configured to determine blade camber corresponding to the blade chord length by using a fitting optimization curve of chord length and camber according to the blade chord length; a module is configured to determine blade height according to the impeller diameter and the blade number; a forming module is configured to obtain a blade primitive according to the blade camber, and stretch the height of a corresponding position of the blade primitive to the blade height to obtain a target blade structure (3); the data acquisition module is connected with the design module, and the design module is connected with the forming module. The method further comprises the following steps: a model acquisition module is configured to obtain a model (2) of a wheel disc and a model (1) of a wheel cover; 8. The blade design system according to claim 7, wherein, an operation module is configured to perform Boolean sum operation on the target blade structure (3), the model (2) of the wheel disc and the model (1) of the wheel cover to determine a final target impeller structure; the operation module is connected with the model acquisition module and the forming module. The blade is a blade obtained by using the blade design method in any one of claims 1-6. ​ 9. A vane, characterized by ​ 10. A high efficiency constant thickness impeller characterized by, comprising the blade of claim 9.

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